已知x2+2x-2=0,先将右式化简,再求值:(x-1)2+(x-3)(x+3)-(x-3)(x-1).
题型:解答题难度:一般来源:不详
已知x2+2x-2=0,先将右式化简,再求值:(x-1)2+(x-3)(x+3)-(x-3)(x-1). |
答案
(x-1)2+(x-3)(x+3)-(x-3)(x-1), =x2-2x+1+x2-9-x2+4x-3, =x2+2x-2, 而已知x2+2x-2=0, 则(x-1)2+(x-3)(x+3)-(x-3)(x-1), =x2+2x-2, =0. |
举一反三
计算:(2x+7)(3x-4)+(3x+5)(3-2x) |
先化简,再求值:(x-2)(x+2)-(x-2)2,其中x=-. |
先化简,再求值:(x+2y)2-2(x-y)(x+y)+2y(x-3y),其中x=-2,y=. |
先化简,再求值:(x-3)(x+4)-(x-x2),其中x=-3. |
最新试题
热门考点