1:What is the solution to f(x)=g(x) ?2:What is the solution to f(x)=g(x) ?3:What is this height?

1 st one    Correct

2 nd one   It is the third graph down....Do you know why?  

      the parabola will be upside down due to the -3/4 leading coefficint

         then sub in some values of x to find which one fits the other  g(x)

             answer 0 and 2      I think you may have gotten confused and put in the 'y' values

                                                 ....the questin asks for the 'x' values where f(x) = g(x)

Equate the two functions (when the two balls are equal height)  and solve for x   (this is the TIME ...not the height)

-4.9x^2 + 12x + 2.5  =  -4.9x^2 + 14 x    

     12x + 2.5 = 14x

2x = 2.5

x = 2.5/2  = 1.25 seconds      is the TIME

   substitute this value of time into one of the equations to find the HEIGHT

       I would substitute into the OTHER equation to see if the answer is the same ....as a check of your answer !