Answer:
y= -1
Explanation:
Because you have the point (3,y), you now know that x is 3 because coordinates come in (x,y) forms. So you would plug in 3 for x. 5(3)-3y=18. Then continue to solve by subtracting 15 from both side and getting -3y=3. Divide from -3 on both sides and get y= -1