求3x^2-2{x-5[x-3(x-2x^2)-3(x^2-2x)]-(x-1)}的值,其中x=-2

问题描述:

求3x^2-2{x-5[x-3(x-2x^2)-3(x^2-2x)]-(x-1)}的值,其中x=-2

原式=3x²-﹛x-5[x-3x+6x²-3x²+6x]-x+1﹜ =3x²-2﹛﹣15x²-20x+1﹜ =3x²+30x²+40x-2 =33x²+40x-2当x=﹣2时, 原式=33×﹙﹣2﹚...