问题
解答题
(1)计算:(-1)2011+3×
(2)先化简,再求值:(
|
答案
(1)(-1)2011+3×
-|1-1 3
|+(3.14-π)03
=-1+
-3
+1+13
=1;
(2)(
-3x x-1
)•x x+1 x2-1 x
=
•x(3x+3-x+1) (x+1)(x-1) (x+1)(x-1) x
=2x+4,
把x=
-2代入上式,2
原式=2x+4=2
-4+4=22
.2