Question

(A) x = 1.

(B) x = {-2, 1}.

(C) x = 2.

(D) x = -1.

(E) x = {-1, 2}.

​

Answer 1

Resposta:

ITEM (B)

Explicação passo-a-passo:

$\blue {{ _{\heartsuit} } \heartsuit_{\heartsuit} } \: \: \mathsf {OI, TUDO \: \: J\acute{O}IA \: ? \: \:\blue {{ _{\heartsuit} } \heartsuit_{\heartsuit} } }$

$\mathtt{ {4}^{x + 1} - 9 \times {2}^{x} + 2 = 0} \\ \mathtt{ {4}^{x} \times 4 - 9 \times {2}^{x} + 2 = 0 } \\ \mathtt{ { {(2}^{2} )}^{x} \times 4 - 9 \times {2}^{x} + 2 = 0 } \\ \mathtt{ { {(2}^{x} )}^{2} \times 4 - 9 \times {2}^{x} + 2 = 0} \\ \mathtt{ {t}^{2} \times 4 - 9t + 2 = 0 } \\ \mathtt{ {4t}^{2} - 9t + 2 = 0 } \\ \mathtt{ {4t}^{2} - t - 8t + 2 = 0} \\ \mathtt{t(4t - 1) - 2(4t - 1) = 0} \\ \mathtt{(4t - 1) \times (t - 2) = 0} \\ \mathtt{4t - 1 = 0} \\ \mathtt{t - 2 = 0} \\ \mathtt{t = \frac{1}{4} } \\ \mathtt{t = 2} \\ \mathtt{ {2}^{x} = \frac{1}{4} } \\ \mathtt{ {2}^{x} = 2} \\\red{\mathtt{x = - 2}} \\ \red{\mathtt{x = 1}}$