Tính tổng :
H= 10/56 + 10/140 + 10/260 + ... + 10/1400
10/56+10/140+10/260+.....+10/1400
Tính tổng:A=10/56+10/140+10/260+.........+10/1400
10/56+10/140+10/260+...+10/1400
A=-10/56+-10/140+-10/260+...+-10/1400
10/56 + 10/140 + 10/260 + ...+ 10/1400
tính: 10/56+10/140+10/260+...+10/1400
A=10/56+10/140+10/260+......+10/1400
tính tổng M=\(\dfrac{10}{56}+\dfrac{10}{140}+\dfrac{10}{260}+....+\dfrac{260}{1400}\)