Đáp án`+`Giải thích các bước giải:

Bài `1`:

`a) x - 2/3 = 6/5 - 3/2`

`x - 2/3 = 12/10 - 15/10`

`x - 2/3 = 12/10 + (-15/10)`

`x - 2/3 = -3/10`

`x = (-3/10) + 2/3`

`x = (-9/30) + 20/30`

`x = 11/30`

`b) 9/4 - x = 2/3 + 1/4`

`9/4 - x = 8/12 + 3/12`

`9/4 - x = 11/12`

`x = 9/4 - 11/12`

`x = 27/12 - 11/12`

`x = 16/12`

`x = 4/3`

`c) x : 3/4 = 4/3 - 1/2`

`x : 3/4 = 8/6 - 3/6`

`x : 3/4 = 5/6`

`x = 5/6 × 3/4`

`x = 15/24`

`x = 5/8`

`d) 5/6 : x = 3/4 + 5/6`

`5/6 : x = 9/12 + 10/12`

`5/6 : x= 19/12`

`x = 5/6 : 19/12`

`x = 5/6 × 12/19`

`x = 60/114`

`x = 10/19`