3. a garage floor measures 150 feet by 120 feet. a scale drawing
of the floor on grid paper uses a scale of 1 unit: 15 feet. what
are the dimensions of the drawing?

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like: