SOLUTION: y + 1 = 0. Please help me. thanks.

You can put this solution on YOUR website!
This is a special case, When you have y=k, where k is a real number and there's no x. Then you have a horizontal line going through k.
y + 1 = 0
y+1-1=0-1
y=-1
You have a horizontal line going through -1, like this:

Happy Calculating!!!