Đáp án:

Giải thích các bước giải:

`1/ 4 : x + 2 /3 = 1 /5`

`<=> 1 /4 : x = − 7/ 15`

`=> x = − 15 /28`

`1/ 4 + 3/ 4 . x = − 7/ 12`

`<=> 3/ 4 . x = − 5 /6`

`=> x = − 10/ 9`

` 7 /3 − 1 /3 : x = 5 /2 `

`<=> 1 /3 : x = − 1/ 6 `

`=> x = − 2 `

`7/ 3 . x − 3 /4 = 7 /6`

`<=> 7/ 3 . x = 23/ 12`

`=> x = 23/ 28`

`7/ 3 . 1/ 3 : x = 5 /2`

`<=> 7/ 9 : x = 5 /2`

`=> x = 14/ 45`

`1/ 5 − 2 /3 + 2 x = 1 /2 `

`<=>− 7/ 15 + 2 x = 1/ 2 `

`<=> 2 x = 29/ 30`

`=> x = 29 /60`

 `1/ 5 ( x − 1/ 4 ) = 3 /2 − 1 /4`

`<=>x − 1 4 = 5/ 4 : 1/ 5`

`<=> x − 1 /4 = 25/ 4 `

`=>x = 13 /2`

`− 5 ( x − 1 /10 ) = 7 /4`

`=> x − 1/ 10 = − 7/ 20`

`=> x = − 1/ 4` 

`− 3 ( 1/ 2 − x ) = − 1/3 − 5 /2`

`<=> 1 /2 − x = − 17/ 6 : ( − 3 ) `

`<=> 1 /2 − x = 17/ 18`

`=> x = − 4 /9`

 $\dcchuyentoan$