tinh
1.3+3.5+5.7+.................+97.99
tính nhanh: D=1.3+3.5+5.7+.......+97.99
1.3 + 3.5 + 5.7 + ... + 97.99
tính : 1.3 + 3.5 + 5.7 +.... + 97.99
A = 1.3 +3.5 + 5.7 + ...+ 97.99
Tính nhanh
B=3^2/1.3+3^2/3.5+3^2/5.7+...+3^2/95.97+3^2/97.99
tính nhanh tổng sau:
b=1.3+3.5+5.7+................+97.99
c=1.2.3+2.3.4+..........+98.99.100
Tính:1.3+3.5+5.7+7.9+......+97.99
4/1.3 + 4/3.5 + 4/5.7 +...+ 4/ 97.99