Question

What number should be added to 17 make the sum 0?

Answer 1

Let x represent that unknown number
x+17=0
Subtract 17 to each side
x+17-17=0-17
x=-17
Check:
-17 add 17=0. As a result,-17 added to 17 to make 0. Hope it help!

Answer 2

-17 would have to be added to 17 to be 0

Hope this helps!