Đáp án:
$a,$ `4/3 + 2/3x - (1/(-2) )^2 = 4 5/12`
`-> 4/3 + 2/3x - 1/4 = 53/12`
`-> 4/3 + 2/3x = 14/3`
`-> 2/3x = 10/3`
`-> x= 5`
Vậy `x = 5`
$b,$ `(5x + 1/4)^2 = 9/16`
`-> (5x + 1/4)^2 = (3/4)^2` hoặc `(5x + 1/4)^2 = (-3/4)^2`
`-> 5x + 1/4 = 3/4` hoặc `5x + 1/4 = -3/4`
`-> 5x = 1/2` hoặc `5x = -1`
`-> x = 1/10` hoặc `x = (-1)/5`
Vậy `x = 1/10` hoặc `x = (-1)/5`
$c,$ `5 - (5 3/8 + x - 7 5/24) : 16 2/3 = 3`
`-> 5 - (43/8 + x -173/24) : 50/3 = 3`
`->(43/8 + x - 173/24) : 50/3 = 2`
`-> 43/8 + x - 173/24 = 100/3`
`-> 43/8 + x = 973/24`
`-> x = 211/6`
Vậy `x = 211/6`
