Alibrary building is in the shape of a rectangle. its floor has a length of (3x + 5) meters and a width of (5x − 1) meters. the expression below represents the area of the floor of the building in square meters:
(3x + 5)(5x − 1)
which of the following simplified expressions represents the area of the floor of the library building in square meters?
28x − 5
15x2 − 5
15x2 + 28x − 5
15x2 + 22x − 5