Question

Solve the following system of linear equations by substitution method:

2x – y = 2

x + 3y =15​

Answer 1

Here, 2x – y = 2

⟹ y = 2x – 2

⟹ x + 3y = 15

Substituting the value of y from (i) in (ii), we get

x + 6x – 6 = 15

⟹ 7x = 21

⟹ x = 3

From (i), y = 2 × 3 – 2 = 4

∴ x = 3 and y = 4

Answer 2

Here, 2x - y = 2

y = 2x – 2

x + 3y = 15

Substituting the value of y from (i) in (ii), we get

x + 6x - 6 = 15

7x = 21

x= 3

From (i), y = 2 3 - 2 = 4

x = 3 and y = 4