$\text{a) 3x³ - 67 = 5³.}$
$\text{⇒ 3x³ - 67 = 125.}$
$\text{⇒ 3x³ = 125 + 67.}$
$\text{⇒ 3x³ = 192.}$
$\text{⇒ x³ = 192 ÷ 3.}$
$\text{⇒ x³ = 64.}$
$\text{⇒ x³ = 4³.}$
$\text{⇒ x = 4.}$
$\text{Vậy x = 4.}$
$\text{b) $5^{3x-2}$ - 2.5 = $5^{3}$.3.}$
$\text{Đề sai em tus ơi!!!!}$
$\text{c) (2x - 17).$5^4$ = $5^{9}$.}$
$\text{⇒ 2x - 17 = $5^{9}$ ÷ $5^4$.}$
$\text{⇒ 2x - 17 = $5^{5}$.}$
$\text{⇒ 2x - 17 = 1953125.}$
$\text{⇒ 2x = 1953125 + 17.}$
$\text{⇒ 2x = 1953142.}$
$\text{⇒ x = 1953142 ÷ 2.}$
$\text{⇒ x = 976571.}$
$\text{Vậy x = 976571.}$
