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NCERT Solutions for Class 7 Maths Chapter 12: Algebraic Expressions - Exercise 12.1

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NCERT Solutions for Class 7 Maths Chapter 12 (EX 12.1)

Free PDF download of NCERT Solutions for Class 7 Maths Chapter 12 Exercise 12.1 and all chapter exercises at one place prepared by expert teacher as per NCERT (CBSE) books guidelines. Class 7 Maths Chapter 12 Algebraic Expressions Exercise 12.1 Questions with Solutions to help you to revise complete Syllabus and Score More marks. Register and get all exercise solutions in your emails. Every NCERT Solution is provided to make the study simple and interesting on Vedantu. Subjects like Science, Maths, English will become easy to study if you have access to NCERT Solution for Class 7 Science , Maths solutions and solutions of other subjects.


Class:

NCERT Solutions for Class 7

Subject:

Class 7 Maths

Chapter Name:

Chapter 12 - Algebraic Expressions

Exercise:

Exercise - 12.1

Content-Type:

Text, Videos, Images and PDF Format

Academic Year:

2024-25

Medium:

English and Hindi

Available Materials:

  • Chapter Wise

  • Exercise Wise

Other Materials

  • Important Questions

  • Revision Notes

Access NCERT Solutions for Maths Class 7 Chapter 12 – Algebraic Expressions

Exercise 12.1

Refer to page 1-22 for Exercise 12.1 in the PDF

1. Get the algebraic expressions in the following cases using variables, constants and arithmetic operations: 

(i) Subtraction of \[z\] from \[y\].

Ans: It is given that the first term is \[y\] and the second term is \[z\]. The operation performed on them is ‘subtraction, therefore 

1st term

2nd term

Operation

Expression

\[y\]

\[z\]

-

\[y - z\]

Thus the expression is \[y - z\].

(ii) One-half of the sum of numbers \[x\] and \[y\]. 

Ans: It is given that the first term is \[x\] and the second term is \[y\]. Operation performed on them is ‘addition’ and then ‘one-half of the sum’, therefore 

1st term

2nd term

Operation 

Expression

\[x\]

\[y\]

+

\[x{\text{  + }}y\]


Term

Operation

Expression

\[x + y\]

One-half, i.e., \[\dfrac{1}{2}\]

\[\dfrac{1}{2}\left( {a + b} \right)\]

Thus the expression is \[\dfrac{1}{2}\left( {x + y} \right)\].

(iii) The number \[z\] multiplied by itself. 

Ans: It is given that the first term is \[z\] and the second term is \[z\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[z\]

\[z\]

\[*\]

\[z * z = {z^2}\]

Thus the expression is \[z * z = {z^2}\].

(iv) One-fourth of the product of numbers \[p\] and \[q\].

Ans: It is given that the first term is \[p\] and the second term is \[q\]. Operation performed on them is ‘multiplication’ and then ‘one-fourth of the product’, therefore 

1st term

2nd term

Operation 

Expression

\[p\]

\[q\]

\[*\]

\[p * q = pq\]


Term

Operation

Expression

\[pq\]

One-fourth, i.e., \[\dfrac{1}{4}\]

\[\dfrac{1}{4}\left( {pq} \right)\]

Thus the expression is\[\dfrac{1}{4}\left( {pq} \right)\].

(v) Numbers \[x\] and \[y\] both squared and added. 

Ans: (a) The first term is \[x\] and the second term is \[x\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[x\]

\[x\]

\[*\]

\[x * x = {x^2}\]


(b)  The First term is \[y\] and the second term is\[y\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[y\]

\[y\]

\[*\]

\[y * y = {y^2}\]


(c)  Now, the first term is \[{x^2}\] and the second term is \[{y^2}\]. Operation performed on them is ‘addition’, therefore 

1st term

2nd term

Operation 

Expression

\[{x^2}\]

\[{y^2}\]

\[ + \]

\[{x^2} + {y^2}\]

Thus the expression is \[{x^2} + {y^2}\].

(vi) Number \[5\] added to three times the product of \[m\] and \[n\]. 

Ans: (a) The first term is \[m\] and the second term is \[n\]. Operation performed on them is ‘addition’, therefore 

1st term

2nd term

Operation 

Expression

\[m\]

\[n\]

\[ + \]

\[m + n\]


(b)  The first term is \[m + n\] and the second term is \[3\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[m + n\]

\[3\]

\[*\]

\[3\left( {m + n} \right)\]


(c)  Now the first term is \[3\left( {m + n} \right)\] and the second term is \[5\]. Operation performed on them is ‘addition’, therefore 

1st term

2nd term

Operation 

Expression

\[3\left( {m + n} \right)\]

\[5\]

\[ + \]

\[3\left( {m + n} \right) + 5\]

Thus the expression is \[3\left( {m + n} \right) + 5\].

(vii) Product of numbers \[y\] and \[z\] subtracted from \[10\]. 

Ans: (a) The first term is \[y\] and the second term is \[z\] . Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[y\]

\[z\]

\[*\]

\[y * z = yz\]


(ii)  The first term is \[y + z\] and the second term is \[10\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[10\]

\[y*z = yz\]

\[ - {\text{ }}\]

\[ 10 - yz\]

Thus the expression is \[ 10 - yz\].

(viii) Sum of numbers \[a\] and \[b\] subtracted from their product.

Ans: (i) The first term is \[a\] and the second term is \[b\] . Operation performed on them is ‘addition’, therefore 

1st term

2nd term

Operation 

Expression

\[a\]

\[b\]

\[ + \]

\[a + b\]


(ii)  The first term is \[a\] and the second term is \[b\]. Operation performed on them is ‘multiplication’, therefore 

1st term

2nd term

Operation 

Expression

\[a\]

\[b\]

\[*\]

\[a*b = ab\]


(iii)  Now, the first term is \[a*b = ab\] and the second term is \[a + b\]. Operation performed on them is ‘subtraction’, therefore 

1st term

2nd term

Operation 

Expression

\[ab\]

\[a + b\]

\[ - \]

\[ab - \left( {a + b} \right)\]

Thus the expression is \[ab - \left( {a + b} \right)\].

2. (i) Identify the terms and their factors in the following expressions, show the terms and factors by tree diagram: 

(a) \[x - 3\]

Ans: Tree diagram of  \[x - 3\] will be:

Tree diagram x-3

(b) \[1 + x + {x^2}\]

Ans: Tree diagram of  \[1 + x + {x^2}\] will be:

Tree diagram

(c) \[y - {y^3}\]

Ans: Tree diagram of  \[y - {y^3}\] will be:

Tree diagram

(d) \[5x{y^2} + 7{x^2}y\]

Ans:  Tree diagram of  \[5x{y^2} + 7{x^2}y\] will be:

Tree diagram

(e) \[ - ab + 2{b^2} - 3{a^2}\]

Ans: Tree diagram of  \[ - ab + 2{b^2} - 3{a^2}\] will be:

Tree diagram

(ii) Identify the terms and factors in the expressions given below:

(a) \[ - 4x + 5\]

Ans: The given expression \[ - 4x + 5\]is achieved when \[ - 4x\] and \[5\] are added, therefore terms of the expression \[ { - 4x + 5} \]are \[ - 4x\] and \[5\].

\[ - 4x\] is achieved by multiplication \[ - 4\] and \[x\]. Therefore, factors of  \[ - 4x\] are \[ - 4\] and \[x\].


(b) \[ { - 4x + 5y} \]

Ans: The given expression\[ - 4x + 5y\] is achieved when \[ - 4x\] and \[5y\] are added, therefore terms of the expression \[ - 4x + 5y\] are \[ - 4x\] and \[5y\].

\[ - 4x\] is achieved by multiplication \[ - 4\]  and \[x\]. Similarly, \[5y\]  is achieved by multiplication \[5\] and \[y\]. Therefore, factors of  \[ - 4x\] are \[ - 4\] and \[x\] and of \[5y\] are \[5\] and \[y\].


(c) \[5y + 3{y^2}\]

Ans: Given expression \[5y + 3{y^2}\] is achieved when \[5y\] and \[3{y^2}\] are added, therefore terms of the expression \[5y + 3{y^2}\] are \[5y\] and \[3{y^2}\].

\[5y\] is achieved by multiplication \[5\] and \[y\]. Similarly, \[3{y^2}\] is achieved by multiplication of \[3\], \[y\] and \[y\]. Therefore, factors of \[5y\] are \[5\] and \[y\] and of \[3{y^2}\] are \[3\], \[y\] and \[y\].


(d) \[xy + 2{x^2}{y^2}\]

Ans: Given expression \[xy + 2{x^2}{y^2}\] is achieved when \[xy\] and \[2{x^2}{y^2}\] are added , therefore terms of the expression \[xy + 2{x^2}{y^2}\] are \[xy\] and \[2{x^2}{y^2}\].

\[xy\] is achieved by multiplication \[x\] and \[y\]. Similarly, \[2{x^2}{y^2}\] is achieved by multiplication of \[2\], \[x\], \[x\], \[y\] and \[y\]. Therefore, factors of \[xy\] are \[x\] and \[y\] and of \[2{x^2}{y^2}\] are  \[2\], \[x\], \[x\], \[y\] and \[y\].


(e) \[pq + q\]

Ans: The given expression \[pq + q\] is achieved when \[pq\] and \[q\] are added , therefore terms of the expression \[pq + q\] are \[pq\] and \[q\].

\[pq\] is achieved by multiplication\[p\] and \[q\]. Therefore, factors of \[pq\] are \[p\] and \[q\].


(f) \[1.2ab - 2.4b + 3.6a\]

Ans: The given expression \[1.2ab - 2.4b + 3.6a\] is achieved when \[1.2ab\], \[ - 2.4b\] and \[3.6a\] are added , therefore terms of the expression \[1.2ab - 2.4b + 3.6a\] are \[1.2ab\], \[ - 2.4b\] and \[3.6a\].

\[1.2ab\] is achieved by multiplication of \[1.2\], \[a\] and \[b\], similarly \[ - 2.4b\] is achieved by multiplication of \[ - 2.4\] and \[b\] and similarly \[3.6a\] is achieved by multiplication of \[3.6\] and \[a\]. Therefore, factors of \[1.2ab\] are \[1.2\], \[a\] and \[b\],  factors of \[ - 2.4b\] are \[ - 2.4\] and \[b\] and of \[3.6a\] are \[3.6\] and \[a\].

(g) \[\dfrac{3}{4}x + \dfrac{1}{4}\]

Ans: The given expression \[\dfrac{3}{4}x + \dfrac{1}{4}\] is achieved when \[\dfrac{3}{4}x\] and \[\dfrac{1}{4}\] are added, therefore terms of the expression \[\dfrac{3}{4}x + \dfrac{1}{4}\] are \[\dfrac{3}{4}x\] and \[\dfrac{1}{4}\].

\[\dfrac{3}{4}x\] is achieved by multiplication of \[\dfrac{3}{4}\] and \[x\]. Therefore, factors of \[\dfrac{3}{4}x\] are \[\dfrac{3}{4}\] and \[x\].

(g) \[0.1{p^2} + 0.2{q^2}\]

Ans: The given expression \[0.1{p^2} + 0.2{q^2}\] is achieved when \[0.1{p^2}\] and \[0.2{q^2}\] are added, therefore terms of the expression \[0.1{p^2} + 0.2{q^2}\] are \[0.1{p^2}\] and \[0.2{q^2}\].

\[0.1{p^2}\] is achieved by multiplication of \[0.1\], \[p\] and \[p\]. \[0.2{q^2}\] is achieved by multiplication of \[0.2\], \[q\] and \[q\]. Therefore, factors of \[0.1{p^2}\] are \[0.1\], \[p\] and \[p\] and of \[0.2{q^2}\] are \[0.2\], \[q\] and \[q\].

3. Identify the numerical coefficients of terms (other than constants) in the following expressions:

(i) \[5 - 3{t^2}\]

Ans: In the expression \[5 - 3{t^2}\], \[5\] is the constant term and \[ - 3{t^2}\] is the term other than the constant. Coefficient of \[ - 3{t^2}\] is \[ - 3\].

(ii) \[1 + t + {t^2} + {t^3}\]

Ans: In the expression \[1 + t + {t^2} + {t^3}\], \[1\] is the constant term and \[t\], \[{t^2}\] and \[{t^3}\] are the terms other than the constant. Coefficient of \[t\] is \[1\], of \[{t^2}\]  is \[1\] and of \[{t^3}\] is \[1\].

(iii) \[x + 2xy + 3y\]

Ans: In the expression \[x + 2xy + 3y\], there is no constant term and \[x\], \[2xy\] and \[3y\] are the terms other than the constant. Coefficient of \[x\] is \[1\], of \[2xy\]  is\[2\] and of \[3y\] is \[3\].

(iv) \[100m + 1000n\]

Ans: In the expression \[100m + 1000n\], there is no constant term and \[100m\] and \[1000n\] are the terms other than the constant. Coefficient of \[100m\] is \[100\] and of \[1000n\] is \[1000\].

(v) \[ - {p^2}{q^2} + 7pq\]

Ans:  In the expression \[ - {p^2}{q^2} + 7pq\], there is no constant term and \[ - {p^2}{q^2}\] and \[7pq\] are the terms other than the constant. Coefficient of \[ - {p^2}{q^2}\] is \[ - 1\] and of \[7pq\] is \[7\].

(vi) \[1.2a + 0.8b\]

Ans:  In the expression \[1.2a + 0.8b\], there is no constant term and \[1.2a\] and \[0.8b\] are the terms other than the constant. Coefficient of \[1.2a\] is \[1.2\] and of \[0.8b\] is \[0.8\].

(vii) \[3.14{r^2}\]

Ans:  In the expression \[3.14{r^2}\], there is no constant term and \[3.14{r^2}\] is the term other than the constant. Coefficient of \[3.14{r^2}\] is \[3.14\].


(viii) \[2\left( {l + b} \right) = 2l + 2b\]

Ans:  In the expression \[2\left( {l + b} \right) = 2l + 2b\], there is no constant term and \[2l\] and \[2b\] are the terms other than the constant. Coefficient of \[2l\] is \[2\] and of \[2b\] is \[2\].


(ix) \[0.1y + 0.01{y^2}\]

Ans:  In the expression \[0.1y + 0.01{y^2}\], there is no constant term and \[0.1y\] and \[0.01{y^2}\] are the terms other than the constant. Coefficient of \[0.1y\] is \[0.1\] and of \[0.01{y^2}\] is \[0.01\].

4. (a) Identify terms which contain \[x\] and give the coefficient of \[x\].

(i) \[{y^2}x + y\].

Ans: In the expression \[{y^2}x + y\], the term which contains \[x\] is \[{y^2}x\]. The coefficient of \[x\] in \[{y^2}x\] is \[{y^2}\].

(ii) \[13{y^2} - 8yx\].

Ans: In the expression \[13{y^2} - 8yx\], the term which contains \[x\] is \[ - 8yx\]. The coefficient of \[x\]in \[ - 8yx\] is \[ - 8y\].


(iii) \[x + y + 2\].

Ans: In the expression \[x + y + 2\], the term which contains \[x\] is \[x\]. The coefficient of \[x\] in \[x\] is \[1\].


(iv) \[5 + z + zx\].

Ans: In the expression \[5 + z + zx\], the term which contains \[x\] is \[zx\]. The coefficient of \[x\] in \[zx\] is \[z\].


(v) \[1 + x + xy\].

Ans: In the expression \[1 + x + xy\], terms which contain \[x\] are \[x\] and \[xy\]. The coefficient of \[x\] in \[x\] is \[1\] and in \[xy\] is\[y\].


(vi) \[12x{y^2} + 25\].

Ans: In the expression \[12x{y^2} + 25\], the term which contains \[x\] is \[12x{y^2}\]. The coefficient of \[x\] in  \[12x{y^2}\] is \[12{y^2}\].


(vii) \[7x + x{y^2}\].

Ans: In the expression \[7x + x{y^2}\], terms which contain \[x\] are \[x{y^2}\] and \[7x\]. The coefficient of \[x\] in  \[x{y^2}\] is \[{y^2}\] and in \[7x\] is \[7\].


(b) Identify terms which contain \[{y^2}\] and give the coefficient of \[{y^2}\].

(i) \[8 - x{y^2}\]

Ans: In the expression \[8 - x{y^2}\], the term which contains \[{y^2}\] is \[ - x{y^2}\]. The coefficient of \[{y^2}\] in \[ - x{y^2}\] is \[ - x\].


(ii) \[5{y^2} + 7x\]

Ans: In the expression \[5{y^2} + 7x\], the term which contains \[{y^2}\] is \[5{y^2}\]. The coefficient of \[{y^2}\]in \[5{y^2}\] is \[5\].


(iii) \[2{x^2}y - 15x{y^2} + 7{y^2}\]

Ans: In the expression \[2{x^2}y - 15x{y^2} + 7{y^2}\], terms which contain \[{y^2}\] are \[ - 15x{y^2}\] and \[7{y^2}\]. The coefficient of \[{y^2}\] in \[ - 15x{y^2}\] is \[ - 15x\] and in \[7{y^2}\] is \[7\].


5. Classify into monomials, binomials and trinomials:

(i) \[4y - 7x\]

Ans: The expression \[4y - 7x\] consists of two terms, i.e., \[4y\] and \[ - 7x\] . Because \[4y - 7x \] consists of two terms. Therefore, \[4y - 7x\] is a binomial.


(ii) \[{y^2}\]

Ans: The expression \[{y^2}\] consists of one term, i.e., \[{y^2}\]. Because \[{y^2}\] consists of one term. Therefore, \[{y^2}\] is a monomial.


(iii) \[x + y + xy\]

Ans: The expression \[x + y + xy\], consists of three terms, i.e., \[x\], \[y\] and \[ - xy\]. Because \[x + y + xy\] consists of three terms. Therefore, \[x + y + xy\] is a trinomial.


(iv) \[100\]

Ans: The expression \[100\] consists of one term, i.e., \[100\]. Because \[100\] consists of one term. Therefore, \[100\] is a monomial.


(v) \[ab - a - b\]

Ans: The expression \[ab - a - b\] consists of three terms, i.e., \[ab\], \[ - a\] and \[ - b\]. Because  \[ab - a - b\] consists of three terms. Therefore, \[ab - a - b\] is a trinomial.


(vi) \[5 - 3t\]

Ans: The expression \[5 - 3t\] consists of two terms, i.e., \[5\] and \[ - 3t\]. Because \[5 - 3t\] consists of two terms. Therefore, \[5 - 3t\] is a binomial.


(vii) \[4{p^2}q - 4p{q^2}\]

Ans: The expression \[4{p^2}q - 4p{q^2}\] consists of two terms, i.e., \[4{p^2}q\] and \[ - 4p{q^2}\]. Because \[4{p^2}q - 4p{q^2}\] consists of two terms. Therefore, \[4{p^2}q - 4p{q^2}\] is a binomial.


(viii) \[7mn\]

Ans: The expression \[7mn\] consists of one term, i.e., \[7mn\]. Because \[7mn\] consists of one term. Therefore, \[7mn\] is a monomial.


(ix) \[{z^2} - 3z + 8\]

Ans: The expression \[{z^2} - 3z + 8\] consists of three terms, i.e., \[{z^2}\], \[ - 3z\] and \[8\]. Because \[{z^2} - 3z + 8\] consists of three terms. Therefore,\[{z^2} - 3z + 8\] is a trinomial.


(x) \[{a^2} + {b^2}\]

Ans: The expression \[{a^2} + {b^2}\] consists of two terms, i.e., \[{a^2}\] and \[{b^2}\]. Because \[{a^2} + {b^2}\] consists of two terms. Therefore, \[{a^2} + {b^2}\] is a binomial.


(xi) \[{z^2} + z\]

Ans: The expression \[{z^2} + z\] consists of two terms, i.e., \[{z^2}\] and \[z\] . Because \[{z^2} + z\] consists of two terms. Therefore, \[{z^2} + z\] is a binomial.


(xii) \[1 + x + {x^2}\]

Ans: The expression \[1 + x + {x^2}\] consists of three terms, i.e., \[1\], \[x\] and \[{x^2}\]. Because \[1 + x + {x^2}\] consists of three terms. Therefore, \[1 + x + {x^2}\] is a trinomial.


6. State whether a given pair of terms is of like or unlike terms:

(i) \[1,{\text{ }}100\]

Ans: Factor of \[1\] is \[1\].

Factor of \[100\] is \[100\].

Algebraic factor \[1\] and \[100\] is none, i.e., and have the same algebraic factor. Therefore, \[1\] and \[100\] are like terms.


(ii) \[ - 7x,{\text{ }}\dfrac{5}{2}x\]

Ans: Factors of \[ - 7x\] are \[ - 7\] and \[x\].

Factors of \[\dfrac{5}{2}x\] are \[\dfrac{5}{2}\] and \[x\] .

Algebraic factor of \[ - 7x\] is \[x\] and of \[\dfrac{5}{2}x\] is \[x\]. Because \[ - 7x\] and \[\dfrac{5}{2}x\] have the same algebraic factor. Therefore, \[ - 7x\] and \[\dfrac{5}{2}x\] are like terms.


(iii) \[ - 29x,{\text{ }} - 29y\]

Ans: Factors of \[ - 29x\] are \[ - 29\] and \[x\].

Factors of \[ - 29y\] are \[ - 29\] and \[y\].

Algebraic factor of \[ - 29x\] is \[x\] and of \[ - 29y\] is \[y\]. Because \[ - 29x\] and \[ - 29y\] do not have the same algebraic factor. Therefore, \[ - 29x\] and \[ - 29y\] are unlike terms.


(iv) \[14xy,{\text{ }}42yx\]

Ans: Factors of \[14xy\] are \[14\], \[x\] and \[y\].

Factors of \[42yx\] are \[42\], \[y\] and \[x\].

Algebraic factors of \[14xy\] are \[x\] and \[y\] and of \[42yx\] are \[y\] and \[x\]. Because \[14xy\] and \[42yx\] have the same algebraic factor, i.e., \[x\] and \[y\]. Therefore, \[14xy\] and \[42yx\] are like terms.


(v) \[4{m^2}p,{\text{ }}4m{p^2}\]

Ans: Factors of \[4{m^2}p\] are \[4\], \[m\], \[m\] and \[p\].

Factors of \[4m{p^2}\] are \[4\], \[m\], \[p\] and \[p\].

Algebraic factors of \[4{m^2}p\] are \[m\], \[m\] and \[p\] and of \[4m{p^2}\] are \[m\], \[p\] and \[p\]. Because \[4{m^2}p\] and \[4m{p^2}\] have different algebraic factors. Therefore, \[4{m^2}p\] and \[4m{p^2}\] are unlike terms.


(vi) \[12xz,{\text{ }}12{x^2}{z^2}\]

Ans: Factors of \[12xz\] are \[12\], \[x\] and \[z\].

Factors of \[12{x^2}{z^2}\] are \[12\], \[x\], \[x\], \[z\] and \[z\].

Algebraic factors of \[12xz\] are \[x\] and \[z\] and of \[12{x^2}{z^2}\] are \[x\], \[x\], \[z\] and \[z\]. Because \[12xz\] and \[12{x^2}{z^2}\] have different algebraic factors. Therefore, \[12xz\] and \[12{x^2}{z^2}\] are unlike terms.


7. Identify like terms in the following:

(a) \[ - x{y^2}, - 4y{x^2},8{x^2},2x{y^2},7y, - 11{x^2}, - 100x, - 11yx,20{x^2}y, - 6{x^2},y,2xy,3x\]

Ans: Factors of \[ - x{y^2}\] are\[ - 1\], \[x\], \[y\] and \[y\]. Algebraic factors of \[ - x{y^2}\] are \[x\], \[y\] and \[y\].

Factors of \[ - 4y{x^2}\] are \[ - 4\], \[y\], \[x\] and \[x\]. Algebraic factors of \[ - 4y{x^2}\] are \[y\], \[x\] and \[x\].

Factors of \[8{x^2}\]  are \[8\], \[x\],  and \[x\]. Algebraic factors of \[8{x^2}\] are \[x\] and \[x\].

Factors of \[2xy\] are \[2\], \[x\] and \[y\]. Algebraic factors of \[2xy\] are \[x\] and \[y\].

Factors of \[7y\] are \[7\] and \[y\]. Algebraic factor of \[7y\] is \[y\].

Factors of \[ - 11{x^2}\] are \[ - 11\], \[x\] and \[x\]. Algebraic factors of \[ - 11{x^2}\] are \[ - 11\], \[x\] and \[x\].

Factors of \[ - 100x\] are  \[ - 100\] and \[x\]. Algebraic factor of \[ - 100x\] is \[x\].

Factors of \[ - 11yx\] are \[ - 11\], \[x\] and \[y\]. Algebraic factors of \[ - 11yx\] are \[x\] and \[y\].

Factors of \[20{x^2}y\] are \[20\], \[x\], \[x\] and \[y\]. Algebraic factors of \[20{x^2}y\] are \[x\], \[x\] and \[y\].

Factors of \[ - 6{x^2}\] are \[ - 6\], \[x\] and \[x\]. Algebraic factors of \[ - 6{x^2}\] are \[x\] and \[x\].

Factor of \[y\] is \[y\]. Algebraic factor of \[y\] is \[y\].

Factors of \[2xy\] are \[2\], \[x\] and \[y\]. Algebraic factors of \[2xy\] are \[x\] and \[y\].

Factors of \[3x\] are \[3\] and \[x\]. Algebraic factor of \[3x\] is \[x\].


One can observe that the following pairs have same algebraic variable, i.e., they are like terms:

\[ - x{y^2} \] and \[ 2x{y^2} \]

\[ - 4y{x^2}\] and \[20{x^2}y\]

\[y\] and \[7y\]

\[ - 100x\] and \[3x\]

\[ - 11yx\] and \[2xy\]

\[8{x^2}\], \[ - 6{x^2}\] and \[ - 11{x^2}\]


(b) \[10pq,7p,8q, - {p^2}{q^2}, - 7pq, - 100q, - 23,12{q^2}{p^2}, - 5{p^2},41,2405p,78pq,13{p^2}q,q{p^2},701{p^2}\]

Ans: Factors of \[10pq\] are \[p\], \[10\] and \[q\]. Algebraic factors of \[10pq\] are \[p\] and \[q\].

Factors of \[7p\] are \[7\] and \[p\]. Algebraic factor of \[7p\] is \[p\].

Factors of \[8q\] are \[8\] and \[q\]. Algebraic factor of \[8q\] is \[q\].

Factors of \[ - {p^2}{q^2}\] are \[ - 1\], \[p\],\[p\] , \[q\] and \[q\]. Algebraic factors of \[ - {p^2}{q^2}\] are \[p\], \[p\], \[q\] and \[q\].

Factors of \[ - 7pq\] are \[ - 7\] , \[q\] and \[p\]. Algebraic factors of \[ - 7pq\]are \[q\] and \[p\].

Factors of \[ - 100q\] are \[ - 100\] and \[q\]. Algebraic factor of \[ - 100q\] is \[q\].

 Factor of \[ - 23\] is \[ - 23\]. Algebraic factor of \[ - 23\] is none.

Factors of \[12{p^2}{q^2}\] are \[12\] , \[q\], \[q\], \[p\] and \[p\]. Algebraic factors of \[12{p^2}{q^2}\] are  \[q\], \[q\], \[p\]and \[p\].

Factors of \[ - 5{p^2}\] are \[ - 5\], \[p\] and \[p\]. Algebraic factors of \[ - 5{p^2}\] are \[p\] and \[p\].

Factor of \[41\] is \[41\]. Algebraic factor of \[41\] is\[41\].

Factors of \[2405p\] are \[2405\] and \[p\]. Algebraic factor of \[2405p\] is \[p\].

Factors of \[78pq \] are \[78\] , \[p\] and  \[q\]. Algebraic factors of \[78pq\]are \[p\] and \[q\].

Factors of \[13{p^2}q\] are \[13\],\[p\],\[p\] and \[q\]. Algebraic factors of \[13{p^2}q\] is  \[p\],\[p\] and \[q\].

Factors of \[q{p^2}\] are \[p\], \[p\] and \[q\]. Algebraic factors of \[q{p^2}\] are \[p\], \[p\] and \[q\].

Factors of \[701{p^2}\] are \[701\], \[p\] and \[p\]. Algebraic factors of \[701{p^2}\] are \[p\] and \[p\].


One can observe that the following pairs have same algebraic variable, i.e., they are like terms:

\[ - 7pq\], \[78pq\] and \[10pq\]

\[2405p\] and \[7p\]

\[ - 100q\] and \[8q\]

\[41\] and \[ - 23 \]

\[701{p^2}\] and \[ - 5{p^2}\]

\[q{p^2}\] and \[13{p^2}q\]

\[ - {p^2}{q^2}\] and \[12{p^2}{q^2}\]

NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Exercise 12.1

Opting for the NCERT solutions for Ex 12.1 Class 7 Maths is considered as the best option for the CBSE students when it comes to exam preparation. This chapter consists of many exercises. Out of which we have provided the Exercise 12.1 Class 7 Maths NCERT solutions on this page in PDF format. You can download this solution as per your convenience or you can study it directly from our website/ app online.

Vedantu in-house subject matter experts have solved the problems/ questions from the exercise with the utmost care and by following all the guidelines by CBSE. Class 7 students who are thorough with all the concepts from the Maths textbook and quite well-versed with all the problems from the exercises given in it, then any student can easily score the highest possible marks in the final exam. With the help of this Class 7 Maths Chapter 12 Exercise 12.1 solutions, students can easily understand the pattern of questions that can be asked in the exam from this chapter and also learn the marks weightage of the chapter. So that they can prepare themselves accordingly for the final exam.

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