如果3!=3x2x1,=5x4x3x2x1,那么100!/99!
1个回答
100!=100*99*98*...1
99!=99*98*97*...*1
所以等于100呗
相关问题
1x1+0x1+2x2+1x2+3x3+2x3+4x4+3x4……99x99+98x99+100x100+99x100
1X1+2X2+3X3+4X4+5X5.+98X98+99X99+100X100=?
1x1一2x2十3x3一4x4十5x5…十99x99一100x100
[1/1x2]+[1/2x3]+[1/3x4]+[1/4x5]+…+[1/99x100].
[1/1x2]+[1/2x3]+[1/3x4]+[1/4x5]+…+[1/99x100].
[1/1x2]+[1/2x3]+[1/3x4]+[1/4x5]+…+[1/99x100].
3x(1x2+2x3+3x4+……+99x100)= (A)97x98x99 (B)98x99x100 (C)99x 1
3x(1x2+2x3+3x4+…+99x100)=
1 1 1 1 1 ——+——+——+——+```````` —— 2X3 3X4 4X5 5X6 99X100
1x2+2x3+3x4+.99x100=?