SAT Question 0f9f8ea7: Nonlinear Functions answer and explanation with Desmos solution

The predicted number of bacteria initially measured in the growth medium is the value of $y$ when $x=0$. Substituting $0$ for $x$ in the given equation yields $y=3,600(a{)}^0$. Since $a$ is positive, this equation is equivalent to $y=3,600(1)$. Therefore, when $x=0$, the value of $y$ is $3,600$. Thus, the predicted number of bacteria initially measured in the growth medium is $3,600$.