Scientists studying a certain species of frog found
that the population is decreasing by 35% each
year. The initial population of frogs was 750. Write
an equation that models the population y of frogs
remaining after x years.
a is the initial population, so a = 750.
b is the decay factor, so b= 35% = 0.35
Substitute for a and bin y = ab.
The equation that models the population y of
frogs remaining after x years is y = 750(0.35).