RD Sharma Class 10 Solutions Chapter 3 - Pair of Linear Equations in Two Variables Exercise 3.9 - Free PDF

The methods for solving linear pairs of equations in two variables can easily solve the difficulties faced by students. To know how to do this correctly, consult the RD Sharma Class 10 Solutions. For any reference relating to this activity, students can use the RD Sharma Solutions for Class 10 Maths Chapter 3 Pair Of Linear Equations In Two Variables Activity 3.9 PDF provided below.

Example: A father's age is three times that of his son's. His age will be double that of his son after twelve years. Determine their current ages.

Solutions:

We Know that the present ages of the father are x years and that of his son’s age as y years.

From the question, 

Father is 3 times as old as his son. 

Hence, the equation formed is

x = 3y

⇒ x – 3y = 0……. (i)

Also, From the question it’s given as,

After 12 years, father’s age will be (x+12) years and son’s age will be (y+12) years.

Furthermore, the relation between their ages after 12 years is given below

x + 12 = 2(y + 12)

⇒ x + 12 = 2y + 24

⇒ x – 2y – 12 = 0…… (ii)

By solving (i) and (ii), we get the solution

By using cross-multiplication, we have

x = 36, y = 12

Therefore, the present age of father is 36 years and the present age of son is 12 years.

Chapter 3: Important Topics RD Sharma Class 10 Solutions

• Systems of two-variable linear equations

• The solution of a two-variable system of linear equations

• Substitution, elimination, and cross-multiplication methods are graphical and algebraic methods for solving a system of linear equations in two variables.

• A system of equations that is both consistent and inconsistent.

• Linear equations in two variables are used to solve simple issues in a variety of fields.

Conclusion

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