The first steps in writing f(x) = 3x2 – 24x + 10 in vertex form are shown.

f(x) = 3(x2 – 8x) + 10

(-8/2)^2 = 16

what is the function written in vertex form?
a. f(x) = 3(x + 4)2 – 6
b. f(x) = 3(x + 4)2 – 38
c. f(x) = 3(x – 4)2 – 6
d. f(x) = 3(x – 4)2 – 38