whats the answer to 18=6-y?

Answer 1

18=6-y

Subtract 6 from both sides you get
12=-y

since your "y" cannot be negative your going to divide by -1 on both sides.

you then have
-12=y

if you were to check this, this is how it would look
18=6-(-12)
18=6+12
18=18