Question

usando apenas log 20 = 1,30, log 30 = 1,47 e log 60 = 1,79, calcule:I]LOG 1.800 -LOG60 ,K] LOG 225+2LOG4, L]LOG 1.200-LOG 20 M]LOG 15 + LOG 40 N] LOG 1.800- LOG 30 O] LOG 20 + LOG 45 yahoo

Answer 1

I) 

Log1800-Log60 

log60.30-log60 
log60+log30-log60 
1,79+1,47-1,79= 1,47   

K) Log225+2Log4
log15²+log16
2log15+4log2
2log30/2+4log20/10
2(log30-log2)+4(log20-log10)
2(log30-log20/10)+4(log20-log10)
2(1,47-[log20-log10])+4(1,30-1)
2(1,47-[1,30-1])+(1,2)
2(1,47-0,30)+1,2
2.1,17+1,2= 1,14  

Encontrando
 Log15 = 1,17
 Log2 =0,30
log1800=3,26
Para ajudar nos próximos cálculos 

L) Log1200-Log20 

Log30.20.2-Log20
Log30+log20+log2-Log20 
1,47+1,30+0,30-1,30 = 2,77

M) Log15+Log40 
1,17+Log20.2
1,17+1,30+0,30 = 2,17 

N) Log1800-Log30 
Log30.60-Log30 
Log1,47+1,79-1,47 = 1,79 

O) Log20+Log45 
1,30+Log15.3
1,30+log15+log3
1,30+15+Log60/20
1,30+1,17+1,79-1,30 = 2,96


Espero ter ajudado!