2x-1>-x 和1/2x

(x-1)(x-2)(x+3)(x+4)>0和(x-1)(x-2)(x+3)(x+4) x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2) {2X+1}+{X} x^2-|x|+1 ｜x-1｜+｜x-2｜ 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) 已知函数f(x)=2/x,x≥2和（x-1)^3,x x/x平方-x+2=2x/x+1 f(x)+g(x)=x2+2x+1,求f(x)和g(x) 1、x(x-y)(x+y)-x(x+y)^2