a, `130^1` - [ 5 . ( 9 - x ) + 53 ] = 47
130 - ( 45 - 5x + 53 ) = 47
130 - ( 98 - 5x ) = 47
130 - 98 + 5x = 47
32 + 5x = 47
5x = 5
x = 1
Vậy x = 1
b, `4^(2x-1)` - 64 = 0
`4^(2x-1)` = 64
`4^(2x-1)` = `4^3`
`=>` 2x - 1 = 3
`=>` 2x = 4
`=>` x = 2
Vậy x = 2
c, `(x-1)^3` - 2 = `5^2`
`(x-1)^3` - 2 = 25
`(x-1)^3` = 27
`(x-1)^3` = `3^3`
`=>` x - 1 = 3
`=>` x = 4
Vậy x = 4
