已知x的2次方+x-1=0,试求x的3次方+2x的2次方+2013的值

2025-05-10 04:29:26
推荐回答(1个)
回答1:

x^2 - x - 1 = 0

x^2 = x + 1

-x^3 + 2x^2 +2013
= (-x^3 + x^2) + x^2 + 2013= -x^2(x - 1) + x^2 + 2013= -(x + 1)(x - 1) + x^2 + 2013= -x^2 + 1 + x^2 + 2013= 2014