SAT Question 637022d2: Linear Equations In Two Variables answer and explanation with Desmos solution

Choice A is correct. The number of birds can be found by calculating the value of $b$ when $r=16$ in the given equation. Substituting $16$ for $r$ in the given equation yields $2.5b+5\left(16\right)=80$, or $2.5b+80=80$. Subtracting $80$ from both sides of this equation yields $2.5b=0$. Dividing both sides of this equation by $2.5$ yields $b=0$. Therefore, if the business cares for $16$ reptiles on a given day, it can care for $0$ birds on this day.