Question

Solve the given pair of linear equations by elimination method.

i) 2x + y – 5 = 0 and 

ii) 3x – 2y – 4 = 0.

Answer 1

In this elimination method, we solve this pair of linear equation by making either of coefficients equal. 

The given equations are 

2x + y = 5 …………….(1) 

3x – 2y = 4 ………..(2) 

To make the coefficients of ‘x’ equal let us multiply the equation (1) by 3 and the equation (2) by (2) on both sides. 

We get 

(2x + y = 5) 3; (3x – 2y = 4) 2

then 2x + y = 5 becomes

2x + 1 = 5 

⇒ 2x = 5 – 1 = 4 

∴ x = 4/2 = 2 So x = 2 

x = 2 and y = 1 are the solutions of the given equations. 

Verification : Put x = 2 and y = 1 in equation (1) and (2) 

2x + y = 5 

2(2) + 1 = 5 

4 + 1 = 5 

5=5

LHS = RHS

3x – 2y = 4 

3(2) – 2(1) = 4 

6 – 2 = 4 

4 = 4 

LHS = RHS