Answer:
4 years
Step-by-step explanation:
subtract 3000 from 24000 then 3000 from the sum of each answer till you get to 12,000
after <u>year 1</u>: $21,000
24,000 - 3,000 = 21,000
after <u>year 2</u>: $18,000
21,000 - 3,000 = 18,000
after <u>year 3</u>: $15,000
18,000 - 3,000 = 15,000
after<u> year 4</u>: $12,000
15,000 - 3,000 = 12,000