Two towns, Morganville and Crowley, had the same population in a given year. Morganville's population increases by 270 people each year, and Crowley's population increases by 120 people each year. In 2010, there are 3,750 people in Morganville and 3,000 people in Crowley. In what year did the two towns have the same population.
Let population when it was the same in both towns be P,
Let number of years since they were the same, be y
Then for Morganville in 2010, we get: P = 3,000 - 270y
And, for Crowley in 2010, we get: P = 3,750 - 120y
It then follows that: 3,000 - 270y = 3,750 - 120y
- 270y + 120y = 3,750 - 3,000
- 150y = 750
As - 5 indicates 5 years prior to 2010, then they had the same population in: