SAT Question cb8f449f: Systems of Linear Equations answer and explanation with Desmos solution

Choice D is correct. Adding the corresponding sides of the two equations eliminates $y$ and yields $x=6$, as shown:

$\frac{1}{2}y=4$

$x-\frac{1}{2}y=2$

Adding these equations gives $x+0=6$.

If ($x$, $y$) is a solution to the system, then ($x$, $y$) satisfies both equations in the system and any equation derived from them. Therefore, $x=6$.