Answer:
10 years
Step-by-step explanation:
Given :
Population of Canyon falls = 22500
Rate of decrease = 740 per year
Population after x years :
f(x) = 22500 - 740x ; x = number of years
Population of Swift Creek = 15200
Rate of Increase = 1500 per year
Population after x years :
f(x) = 15200 + 1500x ; x = number of years
Number of years when, population of swift creek will be twice that of Canyon falls
15200 + 1500x = 2(22500 - 740x)
15200 + 1500x = 45000 - 1480x
15200 - 45000 = - 1480x - 1500x
-29800 = - 2980x
x = 29800 / 2980
x = 10
After 10 years
