Select the correct answer from each drop-down menu.
A plumber uses two different functions to model how much she charges for service calls.
For weekday service calls requiring [tex]$x$[/tex] hours of labor, the amount she charges, in dollars, is modeled by function [tex]$f$[/tex]: [tex]f(x) = 28x + 60[/tex]
For evening or weekend service calls requiring [tex]$x$[/tex] hours of labor, the amount she charges, in dollars, is modeled by function [tex]$g$[/tex]: [tex]g(x) = 50x + 75[/tex]
The function [tex]$\square$[/tex] represents the difference between the amount charged for a service call at 6 p.m. on a Saturday evening and a service call at 11 a.m. on a Tuesday morning.
For a service call lasting 3 hours, the difference in the amounts charged is [tex]$\$[/tex][tex]$ $[/tex]\square$