First, you have to set up two equations.
X + y = 45
18x + 24y = 1,050
To do this, you have to solve for an exponent by cancelling out the other one. To solve for y, you multiply everything in the first equation by -18.
-18x -18y = -810
This cancels out the x and leaves you with 6y = 240. Divide both sides by 6 and you have the number of Yankee hats that were bought.
Then, you have to substitute 40 for y in the first equation and solve for x.
The after 9/4 seconds the football is at its highest point which is 81 feet if Lillian kicks a football. Its height in feet is given by h(t)= -16t²+72t
<h3>What is a parabola?</h3>
It is defined as the graph of a quadratic function that has something bowl-shaped.

Making perfect square:
![\rm h(t)= -[(4t)^2-72t+9^2 -9^2]](https://tex.z-dn.net/?f=%5Crm%20%20h%28t%29%3D%20-%5B%284t%29%5E2-72t%2B9%5E2%20-9%5E2%5D)
![\rm h(t)= -[(4t-9)^2 -81]](https://tex.z-dn.net/?f=%5Crm%20%20h%28t%29%3D%20-%5B%284t-9%29%5E2%20-81%5D)

The highest point will be when term (4t-9)² becomes zero
So the highest point = 81 feet, and it takes:
t = 9/4 seconds
Thus, the after 9/4 seconds the football is at its highest point which is 81 feet if Lillian kicks a football. Its height in feet is given by h(t)= -16t²+72t
Learn more about the parabola here:
brainly.com/question/8708520
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Answer:
96
Step-by-step explanation:
24/ (1 - 3/4)
24 / (1/4)
24 x 4 = 96