Question

determine o valor do logaritmo???
log25 125

log3 (2x+1)=2

Answer 1

E ae Tiago,

nos dois casos use a definição de log:

$log_bc=k~\to~b^k=c\\\\ log_{25}125=x\\ 25^x=125\\ (5^2)^x=5^3\\ \not5^{2x}=\not5^3\\ 2x=3\\\\ \Large\boxed{\boxed{x= \dfrac{3}{2}}}.\\.\\\\\\ log_3(2x+1)=2\\ 2x+1=3^2\\ 2x+1=9\\ 2x=9-1\\ 2x=8\\\\ x= \dfrac{8}{2}\\\\ x=4\\\\\\ \Large\boxed{\boxed{S=\{4\}}}.\\.$

Ótimos estudos mano ;D