Leo bought a car for x dollars one year later the value of the car was 0.88x. which exspression is another way to describe the change in the value of the car.

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: