(-13xy^3)^2*(-6xyz^2)=19x^2y^6*(-6xyz^2)=-23*x^3 *y^7*z^2
(a^2bc^3)^2*abc^2=(a^4b^2c^6)*abc^2=a^5  bc^4
(-12x^4y^2)^3*(2x^3y^3)^4=(-18 x^12y^6)(16x^12y^12)=-2*x^24*y^18
(ab^4c)^3*(-c^2ab)^2=(a^3b^12c^3)*(c^4a^2b^2)=a*b^10*c