Please help I need this so I can pass a test

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Twelve less than a number is at most 20

Kristen is wrapping presents for the holidays. she has a box that measures 4 ft. x 2 ft. x 2 ft. how many square feet of wrapping paper does she need to cover the box without overlapping?