Answer
a. $f(x)=1.25x$
b. $g(x)=21+0.5x$
c. $28$ times, $35$ dollars.
Work Step by Step
a. Without a discount pass, the monthly cost is $f(x)=1.25x$ where $x$ is the number of times using a bus.
b. With a discount pass, the monthly cost is $g(x)=21+0.5x$ where $x$ is the number of times using a bus.
c. Let the above cost to be equal, we have $1.25x=21+0.5x$ which gives $0.75x=21$ and $x=28$ times. The total cost would be $f(28)=1.25(28)=35$ dollars.
