先化简,再求值. (2x-1)2+(x+3)(x-3)-4(x-1),其中x=2

先化简,再求值. (2x-1)2+(x+3)(x-3)-4(x-1),其中x=2.
2024-12-04 04:08:19
推荐回答(1个)
回答(1):

(2x-1)2+(x+3)(x-3)-4(x-1)
=4x2-4x+1+x2-9-4x+4
=5x2-8x-4,
当x=2时,原式=5×22-8×2-4=0.