Question

[phác thảo anh]

A=2\13+2\3.5+2/5.7+.....+2\99.101

Answer 1

[Chính Toàn Phí]

A=2/13+1/3-1/5+1/5-1/7+......+1/99-1/101

A=2/13+1/3-1/101

A=19/39-1/101

A=1919/3939-39/3939

A=1880/3939