What is the perimeter of a yard with length = 4 x + 6 2 x + 1 feet and width = x − 3 2 x + 1 feet? 4 x − 3 4 x + 12 feet 4 x − 3 2 x + 6 feet 8 x − 6 4 x + 12 feet 8 x − 6 2 x + 6 feet