Answer: 2
Step-by-step explanation:
First you have to plug in the value for x which is -18 so then you're equation then get y by itself and solve for y. This becomes
-3(-18) -y = 56
54 - y = 56
-54 -54
Y=2
You can check your work by plugging in 18 for x and 2 for y and when you solve the equation your answer should equal 56.
