化简求值(1)若xm+2n=16,xn=2,(x≠0),求xm+n的值;(2)已知有理x满足x2-x+1=0,求(x-1)3+(x-1)2+(x-1)的值.-数学

题目简介

化简求值(1)若xm+2n=16,xn=2,(x≠0),求xm+n的值;(2)已知有理x满足x2-x+1=0,求(x-1)3+(x-1)2+(x-1)的值.-数学

题目详情

化简求值
(1)若xm+2n=16,xn=2,(x≠0),求xm+n的值;
(2)已知有理x满足x2-x+1=0,求(x-1)3+(x-1)2+(x-1)的值.
题型:解答题难度:中档来源:不详

答案

(1)∵xm+2n=16,
∴xm×(xn)2=16,∵xn=2,
∴xm×4=16,
xm=4,
∴xm+n=xm×xn=4×2=8.

(2)(x-1)3+(x-1)2+(x-1)
=(x-1)(x2+1-2x+x)
=(x-1)(x2-x+1)
∵x2-x+1=0,
∴原式=(x-1)(x2-x+1)=0.

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