已知a^2-5a +1=0,求2a^2-5a +1/a^2的值,
问题描述:
已知a^2-5a +1=0,求2a^2-5a +1/a^2的值,
答
a^2-5a +1=0
-5a+1=-a^2
(2a^2-5a +1)/a^2
=(2a^2-a^2)/a^2
=a^2/a^2
=1