Question

4) Resolva as equações:
a) log 4 x = 2 b) log 2 128 = x

5) Calcule o valor dos logaritmos:
a) log 3 81 b) log 6 36

6) Resolva as equações:

a) log 3 x = 4 b) log x 243 = 5

Answer 1

Oie, Td Bom?!

4.

a)

$log_{4}(x) = 2$

$x = 4 {}^{2}$

$x = 16$

b)

$log_{2}(128) = x$

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

$7 log_{2}(2) = x$

$7 \: . \: 1 = x$

$7 = x$

$x = 7$

5.

a)

$= log_{3}(81)$

$= log_{3}(3 {}^{4} )$

$= 4 log_{3}(3)$

$= 4 \: . \: 1$

$= 4$

b)

$= log_{6}(36)$

$= log_{6}(6 {}^{2} )$

$= 2 log_{6}(6)$

$= 2 \: . \: 1$

$= 2$

6.

a)

$log_{3}(x) = 4$

$x = 3 {}^{4}$

$x = 81$

b)

$log_{x}(243) = 5$

$243 = x {}^{5}$

$x {}^{5} = 243$

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

$x = \sqrt[5]{3 {}^{5} }$

$x = 3$

Att. Makaveli1996