10*(1/2)*(1/3)*(1/4).*(1/2012)*(1/2013)的积是多少

/1/3-1/2/+/1/4-1/3/+/1/5-1/4/+.+/1/10-1/9/ |1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/10-1/9| |1-1/2|-|1/2-1/3|-|1/3-1/4|-.-|1/9-1/10| |1-1/2|+|1/2-1/3|+|1/3-1/4|+...|1/9-1/10| 1+2+3+4*10 计算:(1-1/2)*(1-1/3)*(1-1/4)*……*(1-1/10). 1/1*2*3+1/2*3*4+1/3*4*5+.+1/8*9*10 1+1+2+1+2+3+1+2+3+4+.+1+2+3+...+10急 2/3×3/4×10×1/2 （1+1/2)*(1+1/4)*.*(1+1/10)*(1-1/3)*(1-1/5)*.(1-1/9)简算 (1-1/2^2)*(1-1/3)*(1-1/4^2)*…*(1-1/9^2)*(1/10^2) ((1/2)-1)*((1/3)-1)*((1/4)-1)*((1/5)-1)*((1/6)-1)*((1/7)-1)*((1/8)-1)*((1/9)-1)*((1/10)-1) 1*2/1+2*3/1+3*4/1+...+8*9/1+9*10/1简算 1 1 1 1 1 1 1 1-1 1 1 1 1 2 3 4-1 -1 1 1 1 3 6 10-1 -1 -1 1 1 4 10 20 |3/1-2/1|+|4/1-3/1|+|5/1-4/1|+...+|10/1-9/1|=?3Q （1+1/1*3)*(1+1/2*4)*...*(1+1/8*10)计算 求和：1/1*3+1/2*4+1/3*5+.+1/n(n+1) 1/1*4+1/4*7+1/7*10+.+1/(n+2)(n+1) 1+2x/4-1-3x/10>-1/5