Question

me ajudem pfvr nesses 3 exercícios

Answer 1

8)

$log_{b}(a) = x⇔ {b}^{x} = a$

${a}^{12} = b ⇔ log_{a}(b) = 12$

Alternativa a.

9)

${2}^{2 log_{2}(3) - 3 log_{2}(2) }$

$\frac{ {2}^{2 log_{2}(3) } }{ {2}^{3 log_{2}(2) } } = \frac{ {2}^{ {( log_{2}(3) })^{2} } }{ {2}^{3} } = \frac{ {3}^{2} }{8} = \frac{9}{8}$

Alternativa a

10)

$y = {2}^{ log_{3}(x + 4) }$

Quando y=8

${2}^{ log_{3}(x + 4) } = 8 \\ {2}^{ log_{3}(x + 4) } = {2}^{3} \\ log_{3}(x + 4) = 3 \\ x + 4 = {3}^{3}$

$x + 4 = 27 \\ x = 27 - 4 \\ x = 23$

Alternativa e