Question

A=4/10.12 + 4/12.14 + 4/14.16 + ... + 4/96.98

Answer 1

`A=4/10.12+4/12.14+4/14.16+...+4/96.98`

`=2(2/10.12+2/12.14+2/14.16+...+2/96.98)`

`=2(1/10-1/12+1/12-1/14+1/14-1/16+...+1/96-1/98)`

`=2(1/10-1/98)`

`=2 . 22/245`

`=44/245`

Answer 2

`A=4/(10.12) + 4/(12.14) +  ... + 4/(96.98)`

`= 2 . (2/(10.12) + 2/(12.14) +  ... + 2/(96.98))`

`= 2 . (1/10 - 1/12 + 1/12 - 1/14 +....+ 1/96 - 1/98)`

`= 2. (1/10 - 1/98)`

`= 2 . 22/245`

`= 44/245`