已知X2-5X-14=0求(x-1)×(2x-1)-(x+1)2+1

已知X2-5X-14=0求(x-1)×(2x-1)-(x+1)2+1
已知X2-5X-14=0求(x-1)×(2x-1)-(x+1)2+1

已知X2-5X-14=0求(x-1)×(2x-1)-(x+1)2+1
X2-5X-14=0
X2-5X=14
(x-1)×(2x-1)-(x+1)2+1
=2x^2-2x-x+1-x^2-2x-1+1
=x^2-5x+1
=14+1
=15

...不知道

首先拿十子字相乘法求出x2-5x-14=0 再待入得x1=18 x2=54 你再算一下 我算的快 不一定对