先化简,再求值:(x^3-2x^2+x-4)-(2x^3-5x-4),其中x=-2

2024-12-27 01:26:40
推荐回答(1个)
回答1:

:(x^3-2x^2+x-4)-(2x^3-5x-4)
=x³-2x²+x-4-2x³+5x+4
=-x³-2x²+6x
=-(-2)³-2×﹙-2)²+6×﹙-2)
=8-8-12
=-12