6/5×7 +6/7×9 +6/9×11 +...+6/95×97+6/97×99

Đáp án+Giải thích các bước giải:

`6/{5×7} +6/{7×9} +6/{9×11} +...+6/{95×97}+6/{97×99}` 

`={3xx2}/{5×7} +{3xx2}/{7×9} +{3xx2}/{9×11} +...+{3xx2}/{95×97}+{3xx2}/{97×99}` 

`=3xx{2}/{5×7} +3xx{2}/{7×9} +3xx{2}/{9×11} +...+3xx{2}/{95×97}+3xx{2}/{97×99}` 

`=3xx({2}/{5×7} +{2}/{7×9} +{2}/{9×11} +...+{2}/{95×97}+{2}/{97×99})` 

`=3xx( 1/5 - 1/7 + 1/7 - 1/9 + 1/9 - 1/11 + ... + 1/97 - 1/99 )` 

`=3xx( 1/5 - 1/99 )` 

`=3xx94/495 ` 

`=94/165` 

`#KH`