(4a-b²)·(-2b)=?2ab²·(-3ab)=?

问题描述:

(4a-b²)·(-2b)=?2ab²·(-3ab)=?
4x²y·(-xy²)³=?
(1.3x10^5)(3.8x10³)=?

(4a-b²)·(-2b)=2b³-8ab2ab²·(-3ab)=-6a²b³4x²y·(-xy²)³=4x²y·(-x³y^6)=-4x^5y^7(1.3x10^5)(3.8x10³)=(3.8×1.3)×10^8=4.94×10^8...能不能再详细点,我才刚学到这一章。谢谢(4a-b²)·(-2b)=-8ab+2b^(2+1)=2b³-8ab2ab²·(-3ab)=-6a^(1+1)b^(2+1)=-6a²b³ 4x²y·(-xy²)³=4x²y·(-x³y^6)=-4x^(2+3)y^(1+6)=-4x^5y^7 (1.3x10^5)(3.8x10³)=(3.8×1.3)×10^(5+3)=4.94×10^8