1+(1+2)+(1+2+3)+...+(1+2+...+100) /1x100+2x99+3x98+...+100x1
Tính nhanh:
1+(1+2)+(1+2+3)+(1+2+3+4)+.......+(1+2+3+...+100)/100x1+99x2+98x3+.........+2x99+1x100.
\(\frac{1+\left(1+2\right)+\left(1+2+3\right)+.....+\left(1+2+.....+100\right)}{1x100+1x99+3x98+....+100x1}\)
Tính nhanh:
\(\frac{1+(1+2)+(1+2+3)+(1+2+3+4)+.......+(1+2+3+...+100)}{100x1+99x2+98x3+.........+2x99+1x100}\)
Tính A = 1+( 1+2)+(1+2+3)+..........+(1+2+3+.......+100)
100x1+99x2+97x3+...........+ 2x99+1x100
Tính A = 1+( 1+2)+(1+2+3)+..........+(1+2+3+.......+100)
100x1+99x2+97x3+...........+ 2x99+1x100
Tính giá trị biểu thức bằng cách nhanh nhất
(2000x7,5+2012:3)x(21-3,5x0,25)x(11,2-10-1,2)x(3,75-0,75)/2011+3,14
1+(1+2)+(1+2+3)+(1+2+3+4)+...+(1+2+3+...+100)/100x1+99x2+98x3+...+2x99+1x100
a] A=1x2 +2x3+3x4+...+ 99x100
b]B=1x100+2x99+3x98+99x2+100x1
c] C=1x1+2x2+3x3+...+100x100
Tính A =1+(1+2)+(1+2+3)+........+(1+2+3+..........+100) / 100 x 1+99x2+97x3+...........+ 2x99+1x100