SAT Question 2e1a7f66: Linear Equations In Two Variables answer and explanation with Desmos solution

Choice A is correct. It's given that figure A and figure B (not shown) are both regular polygons and the sum of the perimeters of the two figures is $63$ inches . It's also given that $x$ is the number of sides of figure A and $y$ is the number of sides of figure B, and that the equation $3x+6y=63$ represents this situation. Thus, $3x$ and $6y$ represent the perimeters, in inches, of figure A and figure B, respectively. Since $6y$ represents the perimeter, in inches, of figure B and $y$ is the number of sides of figure B, it follows that each side of figure B has a length of $6$ inches .