1/x-1/(x+2012)怎么算?

1/x-1/(x+2012)怎么算? (x+2)(x+3)-(x+6)(x-1) 怎么算? (x-1)(x-2)(x-3)(x-4)-(x^2-5x)^2-10(x^2-5x)怎么算? 1-x/1+x>0怎么算?) 3^X-1>0 X怎么算 9X=1/X怎么算 X+(X-1)=90,怎么算? (x-3)(x-1)怎么算 ｜x-3|-|x+1|>3怎么算 1/(1-x)+1/(1+x)+2/(1+x*x)+4/(1+x*x*x*x)+8/(1-x*x*x*x*x*x*x*x)怎么做 (x+1)(x-2)-(x-1)的平方怎么算? 1.5x-x=x(1+20%)怎么算? 1.5X+20=1X（50-X)怎么算? 分解因式：(x-1)(x+6)-5x 怎么算?、、、、 x-1/4x=500-x+60 怎么算 x(x-2)+m(1-x)=3怎么算 y+(1+x)(2+x)(3+x)导数怎么算, x∧(1/x) 极限怎么算?x趋向无穷大