Question

check my work please will give medals if you tell if this is right or not!!!
Let f(x)=x+5 and g(x)=x^2. find (g o f) (4)
A. 9 <--- my answer
B. 81
C. 20
D. 1
2. police can estimate the speed of a vehicle before the brakes are applied using the formula 0.75d=s^2/30.25, where s is the speed in miles per hour and d is the length of the vehicle's skid marks. what was the approximate speed of a vehicle that left skid marks measuring 140 feet?
A. about 10 miles per hour <-- my answer
B. about 75 miles per hour
C. about 15 miles per hour
D. about 56 miles per hour
3. you can model the population of a certain city between 1955-2000 by the radial funciton P(x)=55000square root (x-1945). using this model, in which year was the population of that city 220,000?
A. 1949 <--- my answer
B. 1961
C. 1953
D. 1957

4.what is the inverse of f if f(x)=3^square root (x-4)
A. f^-1(x)=x^3+64
B. f^-1(x)=x^3+4 <--- my answer
C. f^-1(x)=4-^3 square root (x)
D. f^-1(x)=1/3^ square root (x-4)