giúp mik với vote 5 *

Đáp án:

`1)` `5x + 1/2 = 2/3`

`<=>` `5x = 2/3 - 1/2`

`<=>` `5x = 4/6 - 3/6`

`<=>` `5x = 1/6`

`<=>` `x = 1/6 : 5`

`<=>` `x = 1/6 . 1/5`

`<=>` `x = 1/30`

Vậy  `x = 1/30`.

`2)` `1/5 - 2/3 + 2x = 1/2`

`<=>` `3/15 - 10/15 + 2x = 1/2`

`<=>` `-7/15 + 2x = 1/2`

`<=>` `2x = 1/2 + 7/15`

`<=>` `2x = 15/30 + 14/30`

`<=>` `2x = 29/30`

`<=>` `x = 29/30 : 2`

`<=>` `x = 29/30 . 1/2`

`<=>` `x = 29/60`

Vậy  `x = 29/60`.

`3)` `2 ( 1/4 - 3x ) = 1/5 - 4x`

`<=>` `1/2 - 6x = 1/5 - 4x`

`<=>` `6x - 4x = 1/2 - 1/5`

`<=>` `2x = 5/10 - 2/10`

`<=>` `2x = 3/10`

`<=>` `x = 3/10 : 2`

`<=>` `x = 3/10 . 1/2`

`<=>` `x = 3/20`

Vậy  `x = 3/20`.

`4)` `5/2 - 3 ( 1/3 - x ) = 1/4 - 7x`

`<=>` `5/2 - 1 + 3x = 1/4 - 7x`

`<=>` `5/2 - 2/2 + 3x = 1/4 - 7x`

`<=>` `3/2 + 3x = 1/4 - 7x`

`<=>` `-3x - 7x = 3/2 - 1/4`

`<=>` `-10x = 6/4 - 1/4`

`<=>` `-10x = 5/4`

`<=>` `x = 5/4 : ( -10 )`

`<=>` `x = 5/4 . ( -1/10 )`

`<=>` `x = -1/8`

Vậy  `x = -1/8`.

`5)` `4 ( 1/3 - x ) + 1/2 = 5/6 + x`

`<=>` `4/3 - 4x + 1/2 = 5/6 + x`

`<=>` `( 4/3 + 1/2 ) - 4x = 5/6 + x`

`<=>` `( 8/6 + 3/6 ) - 4x = 5/6 + x`

`<=>` `11/6 - 4x = 5/6 + x`

`<=>` `4x + x = 11/6 - 5/6`

`<=>` `5x = 6/6`

`<=>` `5x = 1`

`<=>` `x = 1/5`

Vậy  `x = 1/5`.