Question

Quanto vale X em:
7×8^x = 5×7^x​

Answer 1

 Propriedade do logaritmo usada: $x^a = b <=> a = Log_xb$

$7.8^x = 5.7^x\\7.\frac{8^x}{7^x} = 5\\(\frac{8}{7})^x = \frac{5}{7}\\\\x = Log_{\frac{8}{7}}\frac{5}{7}$

Dúvidas só perguntar XD

Answer 2

Resposta:

$7 \times ( \frac{8}{7} ) ^{x} = 5 \\ (\frac{8}{7} ) ^{x} = \frac{5}{7} \\ log_{ \frac{8}{7} }( \frac{5}{7} )$