-18/24-15/21 giải giúp em

2 câu trả lời

$\dfrac{-18}{24}$ `-` `15/21`

`=`  $\dfrac{-18.7}{24.7}$ `-` $\dfrac{15.8}{21.8}$

`=` $\dfrac{-126}{168}$ `-` $\dfrac{120}{168}$

`=` $\dfrac{-126-120}{168}$

`=` $\dfrac{-246}{168}$

`=` $\dfrac{-41}{28}$

`(-18)/24-15/21`

`= (-3)/4-5/7`

`= (-21)/28-20-28`

`= (-41)/28`

`#Jo`