SAT Question c13016f9: Nonlinear Functions answer and explanation with Desmos solution

It's given that the function $f$ is defined by $f\left(x\right)=x^2+x+71$. Substituting $2$ for $x$ in function $f$ yields $f\left(2\right)={\left(2\right)}^2+2+71$, which is equivalent to $f\left(2\right)=4+2+71$, or $f\left(2\right)=77$. Therefore, the value of $f\left(2\right)$ is $77$.