问题 解答题
计算:
(1)
m+2n
n-m
+
n
n-m
-
2m
m-n

(2)
x2
x-1
-x-1
答案

(1)原式=

m+2n
n-m
+
n
n-m
+
2m
n-m

=

m+2n+n+2m
n-m

=

3(n+m)
n-m

(2)原式=

x2
x-1
-
x2-1
x-1

=

x2-x2+1
x-1

=

1
x-1

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