tính tổng : 1x2 + 3x4 + 5x6 + ...... + 99x100
Tinh 1x2+2x3+3x4+...+99x100
Tinh 1x2+2x3+3x4+...+99x100
1x2 + 2x3 + 3x4 + 4x5 + .... +99x100
Tính nhanh: 1x2+2x3+3x4+...+99x100
1/2x3+1/3x4+1/4x5+1/5x6=.......1/99x100
A =1x2+2x3+3x4+...+99x100 = ?
A=1x2+2x3+3x4+4x5+...+99x100
Tính a=1x2+2x3+3x4+...+99x100