1)
a) (3`x` + 1 ) : (-4) = -28
( 3`x` + 1 ) = -28 . (-4)
3`x` + 1 = 112
3`x` = 112-1
3`x` = 111
`x` = 111 : 3
`x` = 37
Vậy `x` = 37
b) `x` - 49 = `5/18`
`x` = `5/18` + 49
`x` = `5/18`+ `882/18`
`x` = `887/18`
c) `23` `x` - `3/4` `x` = 1`1/6`
x ( 23 - `3/4` ) = `7/6`
`x`(`92/4` - `3/4`) = `7/6`
`x` . `89/4` = `7/6`
`x` = `7/6` : `89/4`
`x` = `7/6` . `4/89`
`x` = `14/267`