Answer:
y = -5
Step-by-step explanation:
To solve this, we simply plug in 4 into x and then solve for y. We have:
[tex]-3x+9y=-57\\[/tex]
Now we put 4 into x and do some algebra and solve for the value of y:
[tex]-3x+9y=-57\\-3(4)+9y=-57\\-12+9y=-57\\9y=-57+12\\9y=-45\\y=\frac{-45}{9}\\y=-5[/tex]
So y = -5
