2017天雷降魔杵:x-3/2-2x+1/3=1 /是分数线

计算[(x-1)/(x-2)-(x-2)(x-3)-(x-3)/(x-4)+(x-4)(x-5)]/(2x-7) x*(x/3)=(x-5)*(x/3+1)/2 x=? f(x)=2x(x-1)/(2x-3) x>2求最小值 (x-4)(x-2)-(x-1)(x+3),其中x=-2/5 [(X-2)^3*(X+3)]/(X+1)<0 (x+1/x+2)-(1/x+7)=(x+2/x+3)-(1/x+6) [（x^3-x^2）/(x^2-x)]-[(1-x^2)/(x+1)]的最简公分母是？ （x^3-x^2）/(x^2-x)-(1-x^2)/(x+1)的最简公分母是什么？ 1/(X+1)X+1/(X+1)(X+2)+1/(X+2)(X+3)+1/(X+3)(X+4)=? 求和：1/[(x+1)(x+2)]+1/[(x+2)(x+3)]+1/[(x+3)(x+4)]+1/[(x+4)(x+5)]