0.25/2x+1-0.5/x-2

求1/2x^2-1/4x+0.2x^3+0.25x-0.5x^2-1/5x^3+0.5x-1 其中x=12/13 x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2) 先化简再求值先化简再求值：（x-x/x+1）(x+1/x^2+4x+4)(x^2-4/x^2-2x),其中x=-0.5 {2X+1}+{X} x^2-|x|+1 ｜x-1｜+｜x-2｜ 1/2X^3-1/4X+0.2X^2+0.25x-0.5x^3-1/5x^2的值与x无关 x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4 化简：x(x^2+x)/x^2(x^2-1) x/x平方-x+2=2x/x+1 1、x(x-y)(x+y)-x(x+y)^2