Question

add.
$(8y^{2}+y-9)+(9y^{2}-y-2)$

$(8y^{2}+y-9)+(9y^{2}-y-2)=\square$
(simplify your answer.)

Explanation:

Step1: Remove parentheses

$8y^2 + y - 9 + 9y^2 - y - 2$

Step2: Combine like $y^2$ terms

$8y^2 + 9y^2 + y - y - 9 - 2 = 17y^2 + y - y - 9 - 2$

Step3: Combine like $y$ terms

$17y^2 + (y - y) - 9 - 2 = 17y^2 - 9 - 2$

Step4: Combine constant terms

$17y^2 + (-9 - 2) = 17y^2 - 11$

Answer:

$17y^2 - 11$