Question 61100
Solution:

Given  

3x + y = -7              (1)
 
x - y = -5               (2)

Consider equation (2), we can rewrite the equation (2) as

x + 5 = y                (3)

Substitute the equation (3) in equation (1), we get

3x + (x + 5) = - 7

3x + x + 5 = -7

4x + 5 = -7

4x = - 7 – 5

4x = -12

x = -12 / 4

x = -3                   (4)


Put x = -3 in equation (1), we get

3(-3) + y = -7

-9 + y = - 7

y =  - 7 + 9

y = 2

Therefore the value of x = -3 and y = 2