Question

Answer 1

\(A=\dfrac{1}{7}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{9}+\dfrac{1}{9}-...+\dfrac{1}{28}-\dfrac{1}{29}=\dfrac{1}{7}-\dfrac{1}{29}=\dfrac{22}{203}\)

Answer 2

`A = 1/56 + 1/72 + ..... + 1/812`

  `=  1/( 7*8)+1/(8*9)+....+1/(28*29)`

  `= 1/7 - 1/8 + 1/8 - 1/9 +....+1/28-1/29`

  `= 1/7 - 1/29`

  `= 22/203`