`260 : (x + 4) = 5 . (2^{3} + 5) - 3 . (3^{3} + 2^{2})`
$\Rightarrow$ `260 : (x + 4) = 5 . (8 + 5) - 3 . (27 + 4)`
$\Rightarrow$ `260 : (x + 4) = 5 . 13 - 3 . 31`
$\Rightarrow$`260 : (x + 4) = 65 - 93`
$\Rightarrow$ `260 : (x + 4) = -28`
$\Rightarrow$ `(x + 4) = 260 : (-28)`
$\Rightarrow$ `x + 4 = -65/7`
$\Rightarrow$ `x = -65/7 - 4`
$\Rightarrow$ `x = -93/7`
$\text{Vậy}$ `x = -93/7`