问题
填空题
若x2-3x-2=0,则
|
答案
∵x2-3x-2=0,
∴x2-3x=2,
,(x-1)3-x2+1 x-1
=
,(x-1)2(x-1)-(x+1)(x-1) x-1
=(x-1)2-(x+1),
=x2-3x,
当x2-3x=2时,原式=x2-3x=2.
故本题答案为:2.
若x2-3x-2=0,则
|
∵x2-3x-2=0,
∴x2-3x=2,
,(x-1)3-x2+1 x-1
=
,(x-1)2(x-1)-(x+1)(x-1) x-1
=(x-1)2-(x+1),
=x2-3x,
当x2-3x=2时,原式=x2-3x=2.
故本题答案为:2.