What does labelwhat does label the side length of the region

Graph the equation by plotting point x=2

Select the correct answer from the drop-down menu. subtracting 3xy^2 from 8xy^2 gives the same result as the expression. [tex]3xy ^{2} - 8xy ^{2} [/tex][tex] { - 7xy}^{2} - {2xy}^{2} [/tex][tex] {7xy}^{2} - {2xy}^{2} [/tex]

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15