1 x 2 x 3 x 4 x ...... x 999 x 1000 = 1000!
Đọc là 1000 giai thừa
tính được như thế chắc nổ máy chứ Phạm Hiền Trang
2-1+4-3+6-5+.............+1000-999
1/2*4+1/4*6+.............+1/98*1000
5/2*4+5/4*6+...........+5/98*100
( 1 + 2 + 3 + 4 + 5 + 6 +... + 999 + 1000 ) * ( 0,75 * 0,4 - 3/4 *0,3 )
(1+2+3+4+5+6+...+999+1000)×(0.75×0.4−\(\dfrac{3}{4}\)×0.4)
1+2+3+4+5+6+.........+999+1000=
1 + 2 + 3 + 4 + 5 + ................................................................... + 1000 = X
1 + 3 + 5 + 7 + 9 + ................................................................... + 999 = Y
1 + 4 + 7 + 10 + 13 + ............................................................... + 1000 = Z
X + Y + Z = ?
1+2+3+4+5+6+..............+997+998+999+1000
1+2+3+4+5+6+7+8+9+10+....+999+1000=?
1-1/2+1/3-1/4+......+1/999-1/1000
500-500/501-501/502-502/503-....-999/1000
A = 1+2+3+4+5+6+7.....+999+1000+1001
A = ????????????????
