己知a b=7,a^2 b^2=29求(a-b)^2的值

问题描述:

己知a b=7,a^2 b^2=29求(a-b)^2的值
是a b=7

a^2+ b^2=29,ab=7
(a -b)^2+2ab=29
(a -b)^2=15