Answer:
[tex]y = - 2x + 6[/tex]
Step-by-step explanation:
[tex]since \: f(x) = y \\[/tex]
then the equation reads:
[tex]y = (3 - x)2 \\ y = 6 - 2x \\ [/tex]
The standard form of an quadratic function is:
[tex]y = mx + c \\ [/tex]
So the answer is:
[tex]y = mx + c \\ y = - 2x + 6[/tex]