SAT Question 042aa429: Linear Functions answer and explanation with Desmos solution

Choice C is correct. The value of $f(2)$ can be found by substituting $2$ for $x$ in the given equation $f\left(x\right)=x+7$, which yields $f\left(2\right)=2+7$, or $f\left(2\right)=9$. The value of $g\left(2\right)$ can be found by substituting $2$ for $x$ in the given equation $g\left(x\right)=7x$, which yields $g\left(2\right)=7\left(2\right)$, or $g\left(2\right)=14$. The value of the expression $4f\left(2\right)-g\left(2\right)$ can be found by substituting the corresponding values into the expression, which gives $4(9)-14$. This expression is equivalent to $36-14$, or $22$.