What is the y coordinate of the solution of the system?

Question

What is the y coordinate of the solution of the system?

4x-y=-21

y=x+6

What is the value of y ?

Answer 1

4x - y = -21

y = x + 6

Substitute:

4x -(x + 6) = -21

4x - x - 6 = -21

3x = -15

x = -5

y = 1