Can someone help me out with this please

-8 = -(x + 4)

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? ( )

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

What is the result of adding the system of equations? 2x+y=4 3x-y=6