计算1/1*2 + 1/2*3 1/3*4 +1/4*5 +1/5*6计算1/1*3 +1/3*5 +1/5*7 +1/7*9 +1/9*11化简1/x(x+3) + 1/(x+3)(x+6)+ 1/(x+6)(x+9) +1/(x+9)(x+12)

问题描述:

计算1/1*2 + 1/2*3 1/3*4 +1/4*5 +1/5*6
计算1/1*3 +1/3*5 +1/5*7 +1/7*9 +1/9*11
化简1/x(x+3) + 1/(x+3)(x+6)+ 1/(x+6)(x+9) +1/(x+9)(x+12)