Question

Find the following product:
(y^2+4y-7)(y+3)

Answer 1

\[=y^3+4y^2-7y+3y^2+12y-21\]\[=y^3+7y^2+5y-21\]

Answer 2

(y^2+4y-7)(y+3)



y^2(y+3)+4y(y+3)-7(y+3)



(y^2)(y)+(y^2)(3)+(4y)(y)+(4y)(3)+(-7)(y)+(-7)(3)



y^3+3y^2+4y^2+12y-7y-21



y^3+7y^2+5y-21



So (y^2+4y-7)(y+3)=y^3+7y^2+5y-21