At a concession stand, three hotdogs and two hamburgers cost 8.50, two hotdogs and three hamburgers cost 9.00. what is the cost of one hamburger and one hotdog?

so far i have:
x=hotdog
y-hamburger
3x+2y=8.50
2x+3y=9.00
for the life of me i cannot remember any of the steps past that. any would be awesome.

Which statement explains how you could use coordinate geometry to prove the opposite sides of a quadrilateral are congruent? a. use the slope formula to prove the slopes of the opposite sides are the same. b. use the slope formula to prove the slopes of the opposite sides are opposite reciprocals. c. use the distance formula to prove the lengths of the opposite sides are the same. d. use the distance formula to prove the midpoints of the opposite sides are the same.