Đáp án:
1. `|x/4 - 1/2| = 4/5`
`-> x/4 - 1/2 = 4/5`
hoặc `x/4 - 1/2 = -4/5`
`-> x/4 = 4/5 + 1/2 = 8/10 + 5/10 = 13/10`
hoặc `x/4 = 1/2 - 4/5 = 5/10 - 8/10 = -3/10`
`-> x = 13/10 . 4 = 26/5` hoặc `x = -3/10 . 4 = -6/5`
Vậy `x \in {26/5; -6/5}`
2. `(4/5 + x) - 11/12 = 1/12`
`-> 4/5 + x = 1/12 + 11/12`
`-> 4/5 + x = 1`
`-> x = 1 - 4/5`
`-> x = 5/5 - 4/5`
`-> x = 1/5`
Vậy `x = 1/5`
