Bài 1:
`a,` `-1``1/2` . `-2/5` + `1/6` : `2`
`=` `-3/2` . `-2/5` + `1/12`
`=` `3/5` + `1/12`
`=` `41/60`
`b,` `2`. `5^3` - `3`. `2^3`
`=` `250` `-` `24`
`=` `226`
Bài 2:
`a,` `3/4` + `x` = `-1/2`
`x` = `-1/2` - `3/4`
`x` = `-5/4`
`Vậy` `x` = `-5/4`
`b,` `0, 125` `-` `x` = `1`
`x` = `0, 125` `-` `1`
`x` = `0, 875`
`Vậy` `x` = `0, 875`
`c,` |`x`| `+` `0,225` = `3`
|`x`| = `3` - `0,225`
|`x`| = `2,775`
`=>` $\left[\begin{matrix}x=2,775\\x=-2,775\end{matrix}\right.$
`Vậy` `x` = `2,775` `hoặc` `x` = `2,775`
