10,11 + 11,12+ 12,13+ 13,14+.....+98,99+100
A= 10,11 + 11,12 +12,13 + ....... + 98,99 +100
Tinh' nhanh:10,11+11,12+12,13+13,14+.........+98,99+99,10
tinh :
10,11+11,12+12,13+13,14+.....+98,99+99,10
Tính nhanh tổng sau:
10,11 + 11,12 + 12,13 + 13,14 + ............................ + 98,99 + 100
10,11 + 11,12 + 12,13 +.... + 97,98 + 98,99
10,11+11,12+12,13+....+97,98+98,99+99,100
10,11 + 11,12 + 12,13 + ... + 97,98 + 98,99 + 99,100
S=10,11+11,12+12,13+...+98,99+99,100 =?