计算 ( a - 1 + 1 a + 1 ) ÷ a 2 + 2 a a + 1 .
计算:
(1);
(2).
化简: ( a 2 a - 1 - a - 1 ) ÷ 2 a a 2 - 1 .
化简:.
(1)化简:;
(2)解不等式组,并写出它的正整数解.
计算:.
(1)计算:
(2)化简:
(1)计算:;
(2)计算:.