A population of beetles are growing according to a linear growth model. The initial population (week 0) is $\displaystyle {P}_{{0}}={9}$, and the population after 9 weeks is $\displaystyle {P}_{{9}}={54}$.

Find an explicit formula for the beetle population after $\displaystyle {n}$ weeks.

$\displaystyle {P}_{{n}}$ = Preview Question 6 Part 1 of 2  

After how many weeks will the beetle population reach 134?

Preview Question 6 Part 2 of 2   weeks