Đáp án:
`a)`
`|3/8 - x| +5/6 = 7/4`
` |3/8 - x| = 7/4 -5/6 = 11/12`
TH1
` 3/8 - x = 11/12`
` => x = 3/8 -11/12`
` => x = -13/24`
TH2
` 3/8 - x = -11/12`
` x = 3/8 + 11/12`
` x = 31/24`
Vậy ` x ∈ {-13/24; 31/24}`
`b)`
` (2x-1/3)^2 = (-1/6)^2`
TH1
` 2x -1/3 = 1/6`
` 2x = 1/6 +1/3 = 1/2`
` x = 1/(2) : 2 = 1/4`
TH2
` 2x -1/3 = -1/6`
` 2x = -1/6 +1/3 = 1/6`
` x = 1/(6) : 2 = 1/12`
`c)`
`|x+1| . 2/3 = 1 3/5`
` |x+1| . 2/3 = 8/5`
` |x+1| = 8/5 : 2/3 = 12/5`
TH1
` x+1 = 12/5`
` x = 12/5 - 1 = 7/5`
TH2
`x +1 = -12/5`
` x = -12/5 - 1 `
` x = -17/5`
`d)`
` (2x+1/2)^2 = 1/4 = (1/2)^2 = (-1/2)^2`
TH1
` 2x +1/2 = 1/2`
` 2x = 0`
` x = 0`
TH2
` 2x +1/2 = -1/2`
` 2x = -1/2 -1/2`
` 2x = -1`
` x = -1/2`
