Can someone me with these two questions about logarithms? if you can, don't just tell me the answer. i really want to understand how to do these so add an explanation. and you. ^^

my phone wouldn't let me send the photos so here are the questions:

1. the loudness, l, of a sound in decibels is given by l=10logr, where r is the sound's relative intensity. if the intensity of a certain sound is tripled, by how many decibels does the sound increase?

2. an earthquake rated at 3.5 on the richter scale is felt by many people and an earthquake rated at 4.5 may cause local damage. the richter scale magnitude reading, m, is given by m=logx, where x represents the amplitude of the seismic wave causing ground motion. how many times greater is the amplitude of an earthquake that measures 4.5 than one that measures 3.5?