Đáp án:
`x=24/43`
Giải thích các bước giải:
`4 1/4+2/3:x=5 4/9`
`=>2/3:x=5 4/9-4 1/4`
`=>2/3:x=5+4/9-4-1/4`
`=>2/3:x=(5-4)+(4/9-1/4)`
`=>2/3:x=1+(16/36-9/36)`
`=>2/3:x=1+7/36`
`=>2/3:x=36/36+7/36`
`=>2/3:x=43/36`
`=>x=2/3:43/36`
`=>x=2/3xx36/43`
`=>x=24/43`
Vậy `x=24/43`