17. Find the roots of the quadratic equation x
2 ? 8x = 9 by completing the square. Show your work.

18. Use the discriminant to find the number of real solutions of the equation 3x 2 ? 5x + 4 = 0. Show your work.

A water balloon is tossed into the air with an upward velocity of 25 ft/s. Its height h(t) in ft after seconds is given by the function h(t) = ? 16t
2 + 25t + 3. Show your work.

19. After how many seconds will the balloon hit the ground? (hint: Use the quadratic formula)

20. What will the height be at t = 1 second