Đáp án:
$1/$ `13 1/4 : (-5/7) - 18 1/4 : 5/7`
`= 53/4 : (-5)/7 - 73/4 : 5/7`
`= (-53)/4 . 7/5 - 73/4 . 7/5`
`= 7/5 . ( (-53)/4 - 73/4)`
`= 7/5 . (-126)/4`
`= (-441)/10`
$2/$ `(7 + 3/2 - 1/3) - (1/2 + 2/3 - 2) - (5 + 1/3)`
`= 7 + 3/2 - 1/3 - 1/2 - 2/3 + 2 - 5 - 1/3`
`= (7 + 2 - 5) + (3/2 - 1/2) + (-1/3 - 2/3 - 1/3)`
`= 4 + 1 + (-4)/3`
`= 5 + (-4)/3`
`= 11/3`