Step-by-step explanation:
Given
y = x + 3.....equation 1
y = x - y
or y + y = x
or 2y = x
or y = x / 2......equation 2
Now
Putting equation 2 in equation 1
x / 2 = x + 3
x - x/2 = - 3
2x - x = - 3
2
x / 2 = -3
x = - 6
Now
y = x/ 2
= - 6/2
= - 3
Hope this helps
