若x方-x-1=0.则x四次方分之x三次方+x+1=?
问题描述:
若x方-x-1=0.则x四次方分之x三次方+x+1=?
答
x^2-x-1=0得x^2=x+1
所以
(x^3+x+1)/x^4
=(x^3+x^2)/x^4
=x^2(x+1)/x^4
=(x+1)/x^2
=x^2/x^2
=1