数学计算5xy*(
计算 5xy*(-0.2*x∧2*y∧2)(-3*x∧2*y*z)
5xy×(-0.2*×x²×y²)(-3×x²×y×z) =（5×0.2×3）x^(1+2+2)×y^(1+2+1)×z =3(x^5)(y^4)z