若X的平方减x减1等于零,求x的5次方分之x的4次方加2x加1的值

x² -x -1 =0 即 x² = x+1分母 x^5 = x²*x*x*x= ( x+1)*x*x*x = (x²+x)*x*x= (2x+1)*x*x = (2x²+x )*x= (2(x+1)+x)*x = (3x+2)*x .(1)= (3x²+2x)= 3(x+1) +2x= 5x +3分子x^4 +2x +1 = ...