问题
解答题
(1)计算:(x+1)0-
(2)解方程:2x2-2x-1=0 (3)化简:
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答案
(1)原式=1-2
+3
=1-3
;3
(2)∵2x2-2x-1=0的二次项系数a=2,一次项系数b=-2,常数项c=-1,
∴x=
=-b± b2-4ac 2a
=2± 4+8 4
,1± 3 2
∴x1=
,x2=1+ 3 2
;1- 3 2
(3)原式=
-x-1 (x-1)(x+1) x x(x-1)
=
-1 x+1 1 x-1
=-
.2 (x-1)(x+1)