Hazleorqjacotto7n0 Hazleorqjacotto7n0 21-06-2016 Mathematics contestada What is f(x) = 7x2 + 42x written in vertex form? A. f(x) = 7(x + 6)2 – 6 B. f(x) = 7(x + 6)2 – 42 C. f(x) = 7(x + 3)2 – 9 D. f(x) = 7(x + 3)2 – 63