Answer
$5y(y-2)(y-7)$
Work Step by Step
The product of a binomial sum and a binomial difference is: $(A+B)(A-B)=A^2-B^2$.
The square of a binomial sum is: $(A+B)^2=A^2+2AB+B^2$.
The square of a binomial difference is: $(A-B)^2=A^2-2AB+B^2$.
Hence here: $5y^3-45y^2+70y=\\=5y(y^2-9y+14)\\=5y(y^2-2y-7y+14)\\=5y(y(y-2)-7(y-2))\\=5y(y-2)(y-7)$
