Question

Help with converting vertex form to standard form :)
f(x) = 3(x − 2)^2 + 1
Answers given
f(x) = 3x^2 + 13
f(x) = 3x^2 − 12x + 13
f(x) = 3x^2 + 12x − 11
f(x) = 9x^2 − 36x + 37
If you could explain the steps that would be great. THX

Answer 1

$f(x) = 3(x - 2)^2 + 1\\\\f(x)=3(x^2-4x+4)+1\\\\f(x) = 3x^2-12x+12+1\\\\f(x) = 3x^2-12x+13$