2/ 2.4 + 2/ 4.6 + 2/ 6.8 + 2/ 8.10 + ....... + 2/ 50.52

`2/( 2. 4 ) + 2/( 4. 6 ) + 2/( 6. 8 ) + 2/( 8. 10 ) + .... + 2/( 50 . 52 )`

 `= ( 4 - 2 )/( 2. 4 ) + ( 6 - 4 )/( 4. 6 ) + ( 8 - 6 )/ ( 6.8 ) + ( 10 - 8 )/( 8. 10 ) + ... + ( 52 - 50 )/( 50. 52 )`

`= 4/( 2. 4 ) - 2/( 2. 4 ) + 6/( 4. 6 ) - 4/( 4. 6 ) + 8/( 6. 8 ) - 6/( 6. 8 ) + 10/( 8. 10 ) - 8/( 8. 10 ) + ... + 52/( 50. 52 ) - 50/( 50. 52 )`

`= 1/2 - 1/4 + 1/4 - 1/6 + 1/6 - 1/8 + 1/8 - 1/10 + ... + 1/50 - 1/52`

`= 1/2 - 1/52`

`= 25/52`

$\text{#lknhatminh0322}$

`2/(2.4) + 2/(4.6) + 2/(6.8) + 2/(8.10) + ... + 2/(50.52)`

`= 1/(2.4) + 1/(4.6) + 1/(6.8) + 1/(8.10) + ... + 1/(50.52)`

`= 1/2 - 1/4 + 1/4 - 1/6 + 1/6 - 1/8 + 1/8 - 1/10 + ... + 1/50 - 1/52`

`= 1/2 - 1/52`

`= 25/52`

`#dtkc`