Step-by-step explanation:

Replace x in the equation of f(x) and solve:
f(0) = sqrt(0) = 0
F(49/9) = sqrt(49/9) = 7/3
Answer:
Only one because if it's every 58 miles the next one would be at 116 miles which is higher than 75
A=2
B=9
81-4*2*c = 137
-8c=56
C=-7
2x² + 9x - 7 = 0