40 POINTS Please someone help me with these 3 math questions got a deadline to meet

please give right answers no false

5. Evaluate the function f(x) = 4 ∙ 7^x for x = -1 and x = 2. Show your work

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 25ft/s. Its height H(t) in ft after t 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

5. f(x) = 4 . 7^x

for x = -1

f(-1) = 4 . (7)^-1 = 4/7

for x = 2

f(2) = 4 . (7)^2 = 4 . 49 = 196

17. x^2 - 8x = 9

x^2 -8x + 16 = 9 +16
(x - 4)^2 = 25

(x - 4) = +/-5
x = 5 + 4 = 9 and x = -5 + 4 = -1

18. 3x^2 -5x + 4 = 0

Discriminant √(b^2 - 4ac) = √[(-5)^2 - 4(3)(4)] = √[25 - 48] = √(-23)

Given that √(-23) is an imaginary number, the equation does not have real solutions.

Answer Link