3x^2+5x-12 solved by using quadratic formula

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Step-by-step explanation:

3x^2 + 5x - 12

To solve it, you need an equation, so I think you mean this equation.

3x^2 + 5x - 12 = 0

Using the quadratic formula, you have a = 3, b = 5, c = -12.

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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

b, i believe, but not sure.