已经x满足x^2-2x-1=0,求代数式(2x-1)^2-x(x+4)+(x-2)(x+2)的值

求一下教人妹子学作业 这题我也不会
2025-02-23 18:36:31
推荐回答(1个)
回答1:

(2x-1)^2-x(x+4)+(x-2)(x+2)
=4x²-4x+1-x²-4x+x²-4
=4x²-8x-3
=4x²-8x-4+1
=2(2x²-2x-1)+1
=2*0+1
=1