alyxxboothe alyxxboothe 18-02-2019 Mathematics contestada PLEASE HELPPPPP!!!!!!!! Factor completely 21x3 + 35x2 + 9x + 15. (3x − 5)(7x2 − 3) (3x − 5)(7x2 + 3) (3x + 5)(7x2 − 3) (3x + 5)(7x2 + 3)