What is the slope of the line? pls help

You’re repairing a large rectangular aquarium. the final step is to cover the glass with a protective film. the front and back of the aquarium measure 4 meters by 2 meters, and the sides of the aquarium measure 3 meters by 2 meters. how many square meters of protective film do you need? ( )

X+y=-4 x-y=2 use elimination with adding and subtraction

Do you mind if you guys me with this question i’m on number 8