问题
解答题
计算 (1)
(2)先化简,再求值:(
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答案
(1)原式=5+
--3 2+1
+1 0.2 1 - 3 3
=5-1-5-3
=-1-
;3
(2)原式=
•3a a-1
-(a-1)(a+1) a
•a a+1 (a-1)(a+1) a
=3(a+1)-(a-1)
=3a+3-a+1
=2a+4.
计算 (1)
(2)先化简,再求值:(
|
(1)原式=5+
--3 2+1
+1 0.2 1 - 3 3
=5-1-5-3
=-1-
;3
(2)原式=
•3a a-1
-(a-1)(a+1) a
•a a+1 (a-1)(a+1) a
=3(a+1)-(a-1)
=3a+3-a+1
=2a+4.