Concise Mathematics Class 9 ICSE Solutions for Chapter 6 - Problems on Simultaneous Linear Equations

A linear equation is one in which the variable's maximum power is always 1. A one-degree equation is another name for it. Ax + B = 0 is the conventional form of a linear equation in one variable. A and B are constants, and x is a variable. A linear equation with two variables is written in the conventional form Ax + By = C. A, B, and C are constants, while x and y are variables.

For Example 

8x + 5y = 9

3x + 2y = 4

Solution:

Given equations,

8x + 5y = 9… (1)

3x + 2y = 4… (2)

From (1), we have

y = (9 – 8x)/5

Now,

Putting this value of y in (2)

3x + 2((9 – 8x)/5) = 4

On simplifying, we get

15x + 18 – 16x = 20

x = -2

Substituting the value of x in (1), we get

y = (9 – 8x)/5

= (9 – 8 × -2)/5

= (9 + 16)/5

= 25/5

= 5

Hence, the values of x and y are -2 and 5 respectively.

Important Syllabus Of Selina Concise Mathematics Class 9

The Basic Syllabus For Grade 9

• Chapter 1 – Rational and Irrational Numbers

The fundamentals of mathematics are numbers. Students would have learned about natural numbers, whole numbers, and integers in previous classes. 

• Chapter 2 – Compound Interest (Without Using Formula)

Class 9's Chapter 2 teaches students about interest and how to calculate simple and compound interest without using a formula. 

• Chapter 3 – Compound Interest (Using Formula)

This chapter is a follow-up to Chapter 2. Students were previously taught how to compute compound interest without utilizing a formula.

• Chapter 4 – Expansions

Students learn about the method of evaluating the contents of brackets in Class 9 Chapter 4. It aids pupils in recalling the identities that they were taught in previous classes. 

• Chapter 5 – Factorisation

The concept of factorization is the focus of this chapter. A polynomial is considered a factor of a polynomial when it is expressed as the product of two or more expressions. 

• Chapter 6 – Simultaneous Equations

ax + by + c = 0 is a linear equation with constants a, b, and c and variables x and y. With the help of the solutions PDF, students can have a thorough understanding of the main concepts addressed in this chapter. 

• Chapter 7 – Indices

The notion of Indices (Exponents) is taught in easy-to-understand terms to make learning easier for students. The solutions were created by Vedantu subject matter specialists to assist students in performing well on the Class 9 exams. 

• Chapter 8 – Logarithms

Students can learn how to calculate using logarithms in this lesson. Logarithms are mostly used to simplify difficult calculations. This concept is related to the preceding chapter's topic of Indices (Exponents). 

• Chapter 9 – Triangles

Triangles are the subject of Chapter 9 of Selina Solutions. A triangle is a plane shape with three straight line segments defining it. Triangles have three vertices and three sides. 

• Chapter 10 – Isosceles Triangles

Triangles are the subject of Chapter 9 of Selina Solutions. A triangle is a plane shape with three straight line segments defining it. Triangles have three vertices and three sides. 

• Chapter 11 – Inequalities

In this chapter, the issue of inequalities in triangles is discussed. The properties and difficulties of isosceles triangles are mostly taught to students. 

• Chapter 12 – Midpoint and Its Converse

This chapter follows on from Chapters 10 and 11. Students learn about the mid-point theorem, its converse, and the intercept theorem in this chapter, all of which are significant for exams.