The number of rainbow smelt in Lake Michigan had an
average rate of change of -19.76 per year between 1990
and 2000. The bloater fish population had an average
rate of change of -92.57 per year during the same time. If
the initial population of rainbow smelt was 227 and the
initial population of bloater fish was 1,052, after how
many years were the two populations equal?
The linear function that models the population of
rainbow smelt is y₁ = -19.76x + 227, where
x = the years since 1990 and y₁ = the number of
rainbow smelt.
The linear function that models the population of
bloater fish is y₂ =
The linear equation that determines when the two
populations were equal is
The solution is x =
✓years.