Question

Resolva:

a)3(^)x²+3(^)+¹=24

b)9(^)-2.3(^)x-¹=7

PRECISO URGENTE PRA HOJE!!!!

são apenas 2, e a recompensa é 20 pnts, por favor!!!!

Answer 1

Resposta:

A)

$3 {}^{( {x}^{2}) } + 3 {}^{1} = 24$

$3 {}^{(x {}^{2} )} + 3 = 24$

$3 {}^{(x {}^{2}) } = 24 - 3$

$3 {}^{(x {}^{2} )} = 21$

$log_{3}(3 {}^{(x {}^{2}) } ) = log_{3}(21)$

$x {}^{2} = log_{3}(21)$

$x {}^{2} = log_{ 3}(3.7)$

$x {}^{2} = log_{3}(3) + log_{3}(7)$

$x {}^{2} = 1 + log_{3}(7)$

$x = ± \sqrt{1 + log_{ 3}(7) }$

-

$x = - \sqrt{1 + log_{ 3}(7) } \\ x = \sqrt{1 + log_{3}(7) }$

S [x₁ = - √{1 + log₃(7)} , x₂ = √{1 + log₃(7)} ]

B)

$9 {}^{ - 2} .3 {}^{x - 1} = 7$

$3 {}^{ - 4} .3 {}^{x - 1} = 7$

$3 {}^{x - 5} = 7$

$log_{3}(3 {}^{x - 5} ) = log_{3}(7)$

$x - 5 = log_{ 3}(7)$

$x = log_{3}(7) + 5$