Question

[Uchiha sasuke]

M=\(\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+.....+\frac{10}{1400}\)

tính tổng M

Answer 1

[HoàngbáĐứcTâm3631]

M = 10/56+10/140+10/260+10/1400

M= 5/28+5/70+5/130+5/700

3M/5=1/4-1/7+1/7-1/10+1/10-1/13+...+1/25

3M/5 = 3/14

M= 3/14+5/3=5/14

Answer 2

[HoàngbáĐứcTâm3631]

Mình ghi nhầm