(2yx^2+2yx–3a^2)(y^2x^2)
(2yx^2+2yx-3a^2)(y^2x^2)= (2yx^2)(y^2x^2)=(2yx(Y^2x^2)+(-3a^2)(y^2x^2)=2x^4y^3+2x^3y^3-3a^2x^2y^2=2x^4y^3-3a^2^2y^2+2x^3*y^3