SAT Question fcdf87b7: Nonlinear Equations In One Variable And Systems Of Equations In Two Variables answer and explanation with Desmos solution

For an ordered pair to satisfy a system of equations, both the $x$- and $y$-values of the ordered pair must satisfy each equation in the system. Both expressions on the right-hand side of the given equations are equal to $y$, therefore it follows that both expressions on the right-hand side of the equations are equal to each other: $x^2-4x+4=4-x$. This equation can be rewritten as $x^2-3x=0$, and then through factoring, the equation becomes $x(x-3)=0$. Because the product of the two factors is equal to $0$, it can be concluded that either $x=0$ or $x-3=0$, or rather, $x=0$ or $x=3$. Note that 0 and 3 are examples of ways to enter a correct answer.