SAT Mathematics Practice Test 7

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: ${\mathit{x}}^2-4\mathit{x}+4=4-\mathit{x}$. This equation can be rewritten as ${\mathit{x}}^2-3\mathit{x}=0$, and then through factoring, the equation becomesx(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.