Question 549784


{{{(y^2+4y-7)(y+3)}}} Start with the given expression.



{{{y^2(y+3)+4y(y+3)-7(y+3)}}} Expand.



{{{(y^2)(y)+(y^2)(3)+(4y)(y)+(4y)(3)+(-7)(y)+(-7)(3)}}} Distribute.



{{{y^3+3y^2+4y^2+12y-7y-21}}} Multiply.



{{{y^3+7y^2+5y-21}}} Now combine like terms.



 So {{{(y^2+4y-7)(y+3)}}} expands to {{{y^3+7y^2+5y-21}}}.



In other words, {{{(y^2+4y-7)(y+3)=y^3+7y^2+5y-21}}}.