问题
解答题
计算: ①(-1)2011-|-7|+
②
③
④(
|
答案
①原式=-1-7+3×1+5
=-1-7+3+5
=0;
②原式=
•2m 3n
•9n2 p2 p2 m2n
=
;6 m
③原式=
-2a (a+3)(a-3) (a+3) (a+3)(a-3)
=a-3 (a+3)(a-3)
=
;1 a+3
④原式=
•b-a ab ab (a+b)(a-b)
=-
.1 a+b