The value of Maggie's car decreased by 20% since last year when she bought it if the car is not worth 21,000 how much was the car worth when she bought it

Step-by-step explanation:

You would do 21,000*0.20, which equals 4,200. Since 4,200 equals 20% of 21,000, then you would do 21,000-4,200, which equals 16,800. So the car is worth $16,800 dollars this year.