-5x(-x的平方+2x+1)-(2x+3)(5-x的平方)=
问题描述:
-5x(-x的平方+2x+1)-(2x+3)(5-x的平方)=
答
-5x(-x²+2x+1)-(2x+3)(5-x²)
=5x³-10x²-5x-10x+2x³-15+3x²
=7x³-5x²-15x-15