Will Fan & Medal ;)

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?
A.200x = 10920
B.7720 + 12x = 3200 + 80x
C.7720x + 80 = 3200x + 120
D.7720 + 80x = 3200 + 120x

Question

Will Fan & Medal ;)

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?
A.200x = 10920	
B.7720 + 12x = 3200 + 80x	
C.7720x + 80 = 3200x + 120	
D.7720 + 80x = 3200 + 120x