SAT Question 4b06557b: Systems of Linear Equations answer and explanation with Desmos solution

A solution to a system of equations must satisfy each equation in the system. It follows that if $\left(x,y\right)$ is a solution to the system, the point $\left(x,y\right)$ lies on the graph in the xy-plane of each equation in the system. According to the graph, the point $\left(x,y\right)$ that lies on the graph of each equation in the system is $\left(4,1\right)$. Therefore, the solution to the system is $\left(4,1\right)$. It follows that the value of $x$ is $4$.