Need help!!! how do i do it!!

A modern sculpture in a park contains a parabolic arc that starts at the ground and reaches a maximum height of 10 feet after a horizontal distance of 4 feet. Write a quadratic function (vertex form) that describes the shape of the outside arc, where y is the height of a point on the arc and x is the horizontal distance from the left hand starting point.

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The girls’ softball team is sponsoring a fundraising trip to see a professional baseball game. They charter a 60-passenger bus for $525 In order to make a profit they will charge $15 per person if all seats on the bus are sold, but for each empty seat, they will increase the price by $1.50 per person. Write a quadratic function giving the softball teams profit P(n) from this fund-raiser as a function of the number of passengers is n. what is the minimum number of passengers needed in order for the softball team not to lose money? What is the maximum profit the team can make with this fund-raiser, and how many passengers will it take to achieve this maximum?

Re: Need help!!! how do i do it!!

1.) You know 3 points...(0,0), (4,10), (8,0). Since we know the two roots, we could state $\displaystyle y=kx(x-8)$. Now use the second point to determine *k*.