Đáp án:
`text{Bài 1:}`
$a/$ `(6 - 2 4/5) . 3 1/8 - 1 3/5 : 1/4`
`= (6 - 14/5) .25/8 - 8/5 . 4`
`= 16/5 . 25/8 - 32/5`
`=10 - 32/5`
`= 18/5`
$b/$ `(-5)/7 . 2/11 + (-5)/7 . 9/11 + 1 5/7`
`= (-5)/7 . (2/11 + 9/11) + 12/7`
`= (-5)/7 . 1 + 12/7`
`= (-5)/7 + 12/7`
`= 1`
`text{Bài 2:}`
$a/$ `46 - (x - 11) = -48`
`-> x - 11= 46 + 48`
`-> x - 11=94`
`-> x = 94 + 11`
`-> x = 105`
$b/$ `|x - 3| - 7 = 13`
`-> |x - 3| = 20`
`-> x - 3 = 20` `text{hoặc}` `x - 3 = -20`
`->x = 23` `text{hoặc}` `x = -17`
