1/2×3+1/3×4+1/4×5+……+1/49×50
1/2×3+1/3×4+1/4×5+……+1/49×50
1*2+2*3+3*4+4*5+5*6+……48*49+49*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?
5/(2*1)+5/(2*3)+5/(3*4)……5/(49*50)等于多少
奥数题1+2+3+4+……+49+50
1*1-2*2+3*3-4*4+5*5-6*6+…+49*49-50*50=
1/1×3+1/3×5+1/5×7+…………+1/49×51和1/2×4+1/4×6+1/6×8+…………1/48×50
求1/2+(3/1+2/3)+(1/4+2/4+3/4)+……+(1/50+2/50+3/50+……+48/50+49/
巧算1/1×2+1/2×3+1/3×4+…1/49×50
计算(50/1)(49/1)(48/1)…(4/1)(3/1)(2/1)的值
巧算:50-49+48-47+…+4-3+2-1