Factor completely: 5ab + 3ay + 5b + 3y (1 point) (5b + 3y)(a + 1) (5b - 3y)(a + 1) (5b + 3y)(a - 1) prime 5. factor completely: 4x3 + 28x2 + 7x + 49 (2 points) (x - 7)(4x2 + 7) (x - 7)(4x2 - 7) (x + 7)(4x2 + 7) (x + 7)(4x2 - 7) 6. factor completely: 21x3 + 35x2 + 9x + 15 (2 points) (3x - 5)(7x2 - 3) (3x - 5)(7x2 + 3) (3x + 5)(7x2 - 3) (3x + 5)(7x2 + 3) 7. factor completely: 10xy + 3y + 20ax + 6a (2 points) (10x - 3)(y - 2a) (10x - 3)(y + 2a) (10x + 3)(y + 2a) (10x + 3)(y - 2a)