解(1)：4y×(-2xy²) =4×(-2)×x×y×y² =-8xy³ (2)：(3x²y)³×(-4x) =3³×(x²)³×y³×(-4x) =27×(x^6)×y³×(-4)×x ^表示乘方 =27×(-4)×(x^6)×x×y³ =-108(x^7)y³,8,
