已知多项式A=3x^2-2x+7,B=x^3-8x^2-2,求3A-2B

问题描述:

已知多项式A=3x^2-2x+7,B=x^3-8x^2-2,求3A-2B

A=3x^2-2x+7,B=x^3-8x^2-2,求3A-2B
3A-2B
=9x^2-6x+21-2x^3+16x^2+4
=-2x^3+25x^2-6x+25

3A-2B
=9x^2-6x+21-2x^3+16x^2+4
=-2x^3+25x^2-6x+25