Răspuns:
log15(900)-log15(4)+log4(log3(81))=
=log15(900/4)+log4(log3(3^4))=
=log15(225)+log4(4log3(3))=
=log15(15^2)+log4(4)=
=2log15(15)+1=
=2+1=3
logaA-logaB=loga(A/B)
logaA^n=nlogaA (ex log3(3^4)=4log3(3))
loga(a) =1 (ex log3(3)=1)
logaA=> logaritm in baza a din A
Sper ca intelegii :)))