alonapopovych2005 alonapopovych2005 10-01-2020 Mathematics contestada What is the value of f ( − 3a ), if f ( x ) = 2x 2 + 6x ? Select one: a. 18a 2 - 9a b. 18a 2 - 18a c. 9a 2 - 18a d. 18a - 6a