Question

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

2x – y = 2

x + 3y =15​

Answer 1

Multiply eq 1 by 3

6x - 3y = 6

x + 3y = 15

7x = 21

x = 3

put x= 3 in eq 2

x + 3y = 15

3 + 3y =15

3y = 12

y = 4

{x,y}={3,4} is the solution

Answer 2

Step-by-step explanation:

2x-y =2 (1)

x+3y=15 (2)

take (2) equation.

x+3y=15

x=15-3y (3)

now put the value of x in equation (1)

2(15-3y)-y=2

30-6y-y=2

30-7y=2

-7y=2-30

-7y=-28

y=4

put the value of y in ( 3) equation

x=15-3y

x=15-12

x=3

hence the value of x=3 and y=4