PLEASE HELP WILL GIVE BRAINLIEST AND 30 POINTS This is an assignment in Algebra 1 discussing growth and decay. Specifically car depreciation. Over the years car's prices go down. I basically had to calculate the percentage of how much this car's price dropped. So I calculated what it dropped every year now I need to do every month but I'm not sure how to do that.

First pic: the annual rate
Second pic: my annual rate calculations/percentages
Third pic: what I have so far for the monthly rate but its all wrong because my calculations don't match up but I think it's close