Đáp án:
Bài `2`
` a)`
` x : -5/9 = 3/4 - 1 7/8`
` x : -5/9 = 3/4 - 15/8 = -9/8`
` x = -9/8 . -5/9`
` x =81/40`
`b)`
` 15x - 38 = 94 + 14x`
` 15x - 38 -94- 14x = 0`
` x - 132 = 0`
` x =132`
`c)`
` 2|x-2020| +2019 = 2020`
` 2|x-2020| = 1`
` |x-2020| = 1/2`
Trường hợp `1`
` x -2020 = 1/2`
`=> x= 4041/2`
TH`2`
` x-2020 = -1/2`
` => x= 4039/2`
`d)`
` => (x-1)^2 = 16 = 4^2 = (-4)^2`
TH1
` x-1 = 4 => x= 5`
TH2
` x -1 = -4 => x= -3`
`e)`
` (x-2)^3 = 27`
` (x-2)^3 = 3^3`
` x -2 = 3`
` x =5`
