已知x平减x减1等于零,求x五次方分之x四次方加2 - 知识问答

已知x平减x减1等于零,求x五次方分之x四次方加2x加1的值

1个回答

x²-x-1=0
x²=x+1
x^4
=(x+1)²
=x²+2x+1
=(x+1)+2x+1
=3x+2
x^5
=x^4*x
=(3x+2)*x
=3x²+2x
=3(x+1)+2x
=5x+3
(x^4+2x+1)/x^5
=[(3x+2)+2x+1]/(5x+3)
=(5x+3)/(5x+3)
=1

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