Question

 Tính: A=5/11.16+5/16.21+...+5/61.66

Answer 1

\(=>A=\frac{1}{11}-\frac{1}{16}+\frac{1}{16}-\frac{1}{21}+...+\frac{1}{61}-\frac{1}{66}\)

\(=>A=\frac{1}{11}-\frac{1}{66}\)

\(=>A=\frac{5}{66}\)

li ke nha

Answer 2

A= 5/11.16 + 5/16.21 + .....+5/61.66

A = 1/5.(5/11 - 5/16 + 5/16 - .......5/66)

A = 1/5 . 25/66 = 5/66             

Answer 3

A = 5/11.16 + 5/16.21 + ... + 5/61/66

A = 1/11 - 1/16 + 1/16 - 1/21 + ... + 1/61 - 1/66

A = 1/11 - 1/66

A = 5/66