问题标题:
几道数学计算的化简题(1)(a+1)(a-1)-(a+1)(a+1);(2)1-1/2+1/3-1/4.
问题描述:

几道数学计算的化简题

(1)(a+1)(a-1)-(a+1)(a+1);

(2)1-1/2+1/3-1/4.

沈义回答:
  (1)(a+1)(a-1)-(a+1)(a+1);   =a^2-1-(a^2+2a+1)   =-2a-2   (2)1-1/2+1/3-1/4.   =(12-6+4-3)/12   =7/12
查看更多
数学推荐
热门数学推荐