For which pairs of functions is (f•g)(x)=x?

a. f(x)=x^2 and g(x)=1/x
b. f(x)=2/x and g(x)=2/c
c. f(x)=x-2/3 and g(x)=2-3x
d. f(x)=1/2x-2 and g(x)=1/2x+2

pls

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

The mean of 10 values is 19. if further 5 values areincluded the mean becomes 20. what is the meanthese five additional values? a) 10b) 15c) 11d) 22