alonapopovych2005 alonapopovych2005 09-01-2020 Mathematics contestada What is the value of f ( − 3a ), if f ( x ) = 2x 2 + 4x ? Select one: a. 9a 2 - 12a b. 4a 2 - 9a c. 18a 2 - a d. 18a 2 - 12a