We can write the equation of a line in 3 different forms including slope intercept, point-slope, and standard depending on the information we have. We have a point (8,1) and a slope from the equation y=-23x+5. We will chose point-slope since we have a point and slope.
Point slope:
in our new equation because it us perpendicular to it. This means we will need to change it into its negative reciprocal which is .
We will substitute and .
.
This is the equation of the line perpendicular to y=-23x+5 that crosses through (8,1).
To write the equation you start with the 125 because it is monthly and it doesn't say how often you pay the 75 dollars so the equation would be c(f)=125x+75