Question

What is the product of 4xy and y2 + 2x?

Answer 1

$4xy\cdot(y^2+2x)=(4xy)(y^2)+(4xy)(2x)=4xy^{1+2}+(4\cdot2)x^{1+1}y\\\\=4xy^3+8x^2y=8x^2y+4xy^3$

$\text{Used:}\\\\a^n\cdot a^m=a^{n+m}\\\\a\cdot b=b\cdot a$