SAT Question 4702da8f: Linear Functions answer and explanation with Desmos solution

Choice B is correct. It's given that function $f$ is defined by $f\left(x\right)=80-6x$. The value of $f\left(7\right)$ can be found by substituting $7$ for $x$ in the given function, which yields $f\left(7\right)=80-6\left(7\right)$, or $f\left(7\right)=80-42$, which is equivalent to $f\left(7\right)=38$. Therefore, the value of $f\left(7\right)$ is $38$.