According to the 2000 census the population of canton was 7,720. holly spring's population was 3,200. canton's population increases at a rate of 80 people a year and holly spring's population increases by 120 people a year. which equation may be used to determine the number of years before the populations are equal?

Canton: 7,720 and increases at a rate of 80 people per year.
Holly Spring: 3,200 and increases at rate of 120 people per year.

Let x be the number of years.

Canton = 7,720 + 80x
Holly Spring = 3,200 + 120x

7,720 + 80x = 3,200 + 120x
80x - 120x = 3,200 - 7720
-40x = -4520
x = -4520 / -40
x = 113

It would take 113 years before the populations are equal.

7,720 + 80x = 3,200 + 120x
7,720 + 80(113) = 3,200 + 120(113)
7,720 + 9,040 = 3,200 + 13,560
16,760 = 16,760