Giải thích các bước giải:
$a, 2.3^{2x + 1} = 3⁵⁰ - 3⁴⁹ $
$→ 2.3^{2x + 1} = 3⁴⁹(3 - 1)$
$→ 2.3^{2x + 1} = 3⁴⁹ . 2 $
$→ 3^{2x + 1} = 3⁴⁹$
$→ 2x + 1 = 49$
$→ 2x = 49 - 1$
$→ 2x = 48$
$→ x = 48 : 2$
$→ x = 24$
$Vậy$ $x = 24$
$b, 8.3^{2x+ 4} = 3¹⁰⁰ - 3⁹⁸$
$→ 8 . 3^{2x + 4} = 3⁹⁸(3² - 1)$
$→ 8.3^{2x + 4} = 3⁹⁸(9 - 1)$
$→ 8.3^{2x + 4} = 3⁹⁸ . 8$ $→ 3^{2x + 4} = 3⁹⁸$
$→ 2x + 4 = 98$
$→ 2x = 98 - 4$
$→ 2x = 94$
$→ x = 94 : 2$
$→ x = 47$
$Vậy$ $x = 47$
