Fill in the missing numbers to create an equivalent expression
(21+12) = _ (_+_)

i'm not entirely sure

step-by-step explanation:

if you ask home depot or lowe's they might be able to you out

1. a^4+8a^3+24a^2+32a+16

2.y^8+8y^7+28y^6+56y^5+70y^4+56y^3+28y^2+8y+1

3.x^6-3x^4y^2+3x^2y^4-y^6