问题 解答题
计算:
(1)(a2-1)÷(1-
1
a
)

(2)
a2-1
a2-2a+1
+
2a2-a2
a-2
÷a
答案

(1)(a2-1)÷(1-

1
a
)

=(a+1)(a-1)÷

a-1
a

=(a+1)(a-1)×

a
a-1

=a2+a;

(2)

a2-1
a2-2a+1
+
2a2-a2
a-2
÷a

=

(a+1)(a-1)
(a-1)2
+
a2
a-2
×
1
a

=

a+1
a-1
+
a
a-2

=

2a2-2a-2
(a-1)(a-2)

判断题
名词解释