问题
解答题
(1)计算:-12-(-
(2)先化简,再求值:
|
答案
(1)原式=-1-4+1+2
=-2;
(2)原式=
+(a+3)(a-3) a(a-3) (1-a)2 a(a-1)
=
+a+3 a a-1 a
=
.2a+2 a
当a=
时,原式=2
=2+2
+22 2
.2
(1)计算:-12-(-
(2)先化简,再求值:
|
(1)原式=-1-4+1+2
=-2;
(2)原式=
+(a+3)(a-3) a(a-3) (1-a)2 a(a-1)
=
+a+3 a a-1 a
=
.2a+2 a
当a=
时,原式=2
=2+2
+22 2
.2