Question

Considerando log2=0,3, log3=0,48 e log5=0,7, use as propriedades operatórias e calcule o valor dos seguintes logaritmos

a) log25 192

b) log15 180

Answer 1

Boa noite 

log(2) = 0.3
log(3) = 0.48
log5) = 0.7 

log25(192) = log(2*81)/log(25) 
log25(192) = log(2)/2log(5) + 4log(3)/2log(5)
log25(192) = 0.3/(2*0.7) + 4*0.48/(2*0.7)
log25(192) = 1.5857

b) 

log15(180) = log(180)/log(15)
log15(180) = log(9*4*5)/(log(3) + log(5))
log15(180) = (0.96 + 0.6 + 0.7)/(0.48 + 0.7)
log15(180) = 1.91525