SAT Question 3ea87153: Nonlinear Functions answer and explanation with Desmos solution

Choice A is correct. It's given that $g\left(x\right)=x^2+9$. Substituting $25$ for $g\left(x\right)$ in this equation yields $25=x^2+9$. Subtracting $9$ from both sides of this equation yields $16=x^2$. Taking the square root of each side of this equation yields $x=\pm 4$. It follows that $g\left(x\right)=25$ when the value of $x$ is $4$ or $-4$. Only $4$ is listed among the choices.