若x^2+7x-8=0,则x-(8/x)=
问题描述:
若x^2+7x-8=0,则x-(8/x)=
答
x^2+7x-8=0
(x-1)(x+8)=0
x1=1 x2=-8
x-(8/x)=1-(8/1)=-7
x-(8/x)=-8-(8/-8)=-7