( 24x + $5^3$ ) - 4.$5^4$ = $5^4$
$\Rightarrow$ ( 24x + 125 ) - 4.625 = 625
$\Rightarrow$ ( 24x + 125 ) - 2500 = 625
$\Rightarrow$ 24x + 125 = 625 + 2500
$\Rightarrow$ 24x + 125 = 3125
$\Rightarrow$ 24x = 3125 - 125
$\Rightarrow$ 24x = 3000
$\Rightarrow$ x = 3000 : 24
$\Rightarrow$ x = 125
Vậy x = 125