当x=11/75 ,y=25/44 求(x+y)^-(x-y)^的值
问题描述:
当x=11/75 ,y=25/44 求(x+y)^-(x-y)^的值
江湖救急
答
(x+y)^2-(x-y)^2
=x^2+y^2+2xy-(x^2+y^2-2xy)
=4xy
=4×11/75×25/44
=25/75
=5/15
=1/3