Question

Q. Solve the following system of linear equations by substitution method:

2x – y = 2

x + 3y =15​

Answer 1

Answer:

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

&therefore ; x = 3 and y = 4

Answer 2

Given system of equations:

2x - y = 2.................[1]

and, x + 3y = 15 ...........................[2]

•From Equation[1],we get:

2x - y = 2

→y = 2x - 2

•Putting y in equation[2],we get:

x + 3(2x - 2) = 15

→7x - 6 = 15→7x = 21

→x = 3

•Putting x in y = 2x - 2,we get:

y = 2(3) - 2

→y = 6 - 2

→y = 4

The solutions of the equations in the system are 3 and 4