What is the equation of the function in vertex form?

Your correct answer is -b/2a

Step-by-step explanation:

What you need to do is  find the coordinates of the vertex from the equation itself, using this formula: x = -b/2a

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you