问题
解答题
计算: (1)
(2)
(3)(2ab2c-3)-2÷(a-2b)3 (4)
(5)
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答案
(1)原式=
-x2 x-1 x+1 1
=
-x2 x-1 (x+1)(x-1) x-1
=x2-(x2-1) x-1
=
;1 x-1
(2)原式=2+1+3+2=8;
(3)原式(2ab2c-3)-2•(a-2b)-3
=
a-2 b-4c6•a6b-31 4
=
a4b-7c61 4
=
;a4c6 4b7
(4)原式=
÷(x+y)(x-y) x x2-2xy+y2 x
=
•(x+y)(x-y) x x (x-y)2
=
;x+y x-y
(5)原式=
+6 (x+3)(x-3) x-3 (x+3)(x-3)
=x+3 (x+3)(x-3)
=
.1 x-3