Question

resolva as Equacoes Exponenciais : b: 3×=1/27 , c: 4.2×=1/16

Answer 1

b) 3×=1/27
3×=1/3^3
3×=3^-3
x= -3

c) 4.2×= 1/16
8×=1/16
(2^3)×= 1/2^4
2^3x = 2^-4
3x= -4
x=-4/3

Answer 2

$b) 3^{x}= \frac{1}{27} \\ \\ 3^{x}= \frac{1}{3^{3}} \\ \\ 3^{x}=3^{-3} \\ \\ x = -3 \\ \\ c) 4.2^{x}= \frac{1}{16} \\ \\ 2^{x}= \frac{1}{ \frac{16}{4} } \\ \\ 2^{x}= \frac{1}{64} \\ \\ 2^{x}= \frac{1}{2^{6}} \\ \\ 2^{x}=2^{-6} \\ \\ x = -6$

Espero ter ajudado.