Each issue of Soccer World magazine costs $5.99 at the book store. A 6-month subscription costs $24.99. How much can a reader save by subscribing to the magazine for 6 months?

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: