已知x=22/75,y=25/44,求(x+y)-(x-y)
问题描述:
已知x=22/75,y=25/44,求(x+y)-(x-y)
答
(x+y)-(x-y) =[(x+y)+(x-y)][(x+y)-(x-y)]=(2x)(2y)=4xy=4×22/75×25/44=2/3
已知x=22/75,y=25/44,求(x+y)-(x-y)
(x+y)-(x-y) =[(x+y)+(x-y)][(x+y)-(x-y)]=(2x)(2y)=4xy=4×22/75×25/44=2/3