2(3/2-x)-1/3=7x–1/4 1/5(-3/5–10)+5x=x–2/3

Đáp án: `x = 35/108`

             `x = 109/300 `

Giải thích các bước giải:

* ` 2( 3/2 – x ) – 1/3 = 7x – 1/4 ` *

`⇒ ( 2 . 3/2 – 2x ) – 1/3 = 7x – 1/4 `

`⇒ ( 3 – 2x ) – 1/3 = 7x – 1/4 `

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

`⇒ 8/3 – 2x = 7x – 1/4  ` 

`⇒ ( 7x – 1/4 ) –  8/3 + 2x  = 0` ( áp dụng quy tắc chuyển vế ) 

`⇒ ( 7x + 2x ) + ( -1/4 – 8/3 ) = 0 `

`⇒ 9x + (-35/12 )= 0`

`⇒ 9x = 35/12  `

`⇒ x =  35/12  : 9 = 35/108 `

* `1/5 .( -3/5 – 10) + 5x = x – 2/3` *

`⇒ [ 1/5 . ( -3/5 ) – 1/5 . 10 ] + 5x = x – 2/3 `

`⇒ ( -3/25 – 2 ) + 5x = x – 2/3 `

`⇒ -53/25 + 5x = x – 2/3 `

`⇒ ( -53/25 + 5x ) + 2/3 = x `

`⇒ ( -53/25 + 2/3 ) + 5x = x`

`⇒ -109/75 + 5x = x `

`⇒ -109/75 + 5x – x = 0 `

`⇒ -109/75 + 4x = 0 `

`⇒ 109/75 = 4x `

`⇒ x = 109/75 : 4 = 109/300`