Question

How do you combine like terms in `(y ^ { 2} - 15y + 20) + ( - y ^ { 2} + 8y - 16)`?

Answer 1

`-7y+4`

Explanation:

Combine same variable first:
`y^2+(-y^2)-15y+(+8y)+20+(-16)`
And make it:
`y^2-y^2-15y+8y+20-16 = -7y+4`