So basically, the first question after the word problem is asking you to write an equation to represent the value of Mama's car after a certain amount of years (t). Since the value of her car decreases by 3% each year, you could multiply 3% by the original value of her car, to find what 3% is, OR you could subtract 19,400 (the value of her car after 1 year) from 20,000 INSTEAD of multiplying 20,000 by 3%.
Equation: value=20,000 - 600t
To answer the next question, just plug it into the equation you created.
500<20,000 - 600t
-19500< -600t
32.5>t Final Answer: It would take at least 32 and 1/2 years for the value of Mama's car to be less than $500.
