Giải thích các bước giải:
a) X + `4/9` = `5/2` + `1/3`
X + `4/9` = `17/6`
X = `17/6` - `4/9` = `43/18`
b)`4/5` - X = `1/5` x `2/3`
`4/5` - X = `2/15`
X = `4/5` - `2/15`= `2/3`
c)3 - X x `1/2` = `1/3`
X x `1/2` = 3 - `1/3` = `8/3`
X = `8/3` : `1/2`= `16/3`