Bài1: tìm x, biết

a, 2/9 + x : 3/4 = 1/18 + 2/3

b, 4/5 : x - 3/5 = 2/3 - 1/5

c, 7/3 . X = 4/9 = 1/2 + 2/3

d, x .7/6 + 5/6 = 3/2 - 1/3

Đáp án `+` Giải thích các bước giải`:`

`a, 2/9 + x: 3/4 = 1/18 +2/3`

`2/9 + x:3/4= 13/18`

`x:3/4=13/18-2/9`

`x:3/4=1/2`

`x=1/2 . 3/4`

`x=3/8`

Vậy `x=3/8`

`b, 4/5 : x -3/5 = 2/3 -1/5`

`4/5 :x -3/5=7/15`

`4/5 : x=7/15+3/5`

`4/5 :x=16/15`

`x=4/5 : 16/15`

`x=3/4`

Vậy `x=3/4`

`c, 7/3 . x -4/9 = 1/2 +2/3`

`7/3 . x -4/9=7/6`

`7/3 . x= 7/6+4/9`

`7/3 . x=29/18`

`x=29/18 : 7/3`

`x=29/42`

Vậy `x= 29/42`

`d, x . 7/6 +5/6=3/2-1/3`

`x . 7/6 + 5/6= 7/6`

`x. 7/6= 7/6 -5/6`

`x . 7/6=1/3`

`x= 1/3 : 7/6`

`x= 2/7`

Vậy `x=2/7`