问题 解答题
计算下列各题.
(1)(2a-1b22•(-a2b3)•(3ab-23
(2)(
x
x-2
-
x
x+2
4x
2-x

(3)
x2-1
x2-2x+1
+
x2-2x
x-2
÷x

(4)
a2+a
a-1
÷(a-
a
a-1
)
答案

(1)原式=4a-2b4•(-a2b3)•27a3b-6

=-108a3b;

(2)原式=

x(x+2)-x(x-2)
(x-2)(x+2)
2-x
4x

=

4x
(x-2)(x+2)
2-x
4x

=-

1
x+2

(3)原式=

(x+1)(x-1)
(x-1)2
+
x(x-2)
x-2
1
x

=

x+1
x-1
+1

=

2x
x-1

(4)原式=

a(a+1)
a-1
÷
a(a-1)-a
a-1

=

a(a+1)
a-1
÷
a(a-2)
a-1

=

a(a+1)
a-1
a-1
a(a-2)

=

a+1
a-2

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