@Thỏ
`(27 times 13 + 18 times 13) : (9 2/3 + x) = 13`
`-> [13 . (27 + 18)] : ( 9 2/3 + x) = 13`
`-> [13 . 45] : (9 2/3 + x) = 13`
`-> 585 : (9 2/3 + x) = 13`
`-> 9 2/3 + x = 585 : 13`
`-> 9 2/3 + x = 45`
`-> 29/3 + x = 45`
`-> x = 45 - 29/3`
`-> x = 35 1/3 = 106/3`