1/1*2+1/2*3+1/3*4+…+1/49*50=?
巧算1/1×2+1/2×3+1/3×4+…1/49×50
1/2×3+1/3×4+1/4×5+……+1/49×50
计算(50/1)(49/1)(48/1)…(4/1)(3/1)(2/1)的值
数学计算题(急!):1/(1*2*3)+1/(2*3*4)+……+1/(48*49*50)=
1*1-2*2+3*3-4*4+5*5-6*6+…+49*49-50*50=
1/2*3+1/3*4+1/4*5……+1/48*49+1/49*50是多少
2×1/1+2×3/1+3×4/1+4×5/1+……49×50/1怎么解?
奥数题1+2+3+4+……+49+50
1/1*2 + 1/2*3 + 1/3*4 .+ 1/49*50=?
1/1*2+1/2*3+1/3*4+.+1/49*50=?解题思路
求1/2+(3/1+2/3)+(1/4+2/4+3/4)+……+(1/50+2/50+3/50+……+48/50+49/
1*2+2*3+3*4+4*5+5*6+……48*49+49*50