Abe, a plumber, charges $50 per hour plus $75 for making an in-home visit. the plumbing service charges $65 per hour but no set fee for a visit. how many hours of plumbing work are needed for each to cost the same?

Steps:

let “x” be number of hrs
let “y” be total cost

Abe:

50x + 75 = y

Plumbing Service:

65x=y

Since both equations are equal to y, you can set them equal to each other.

65x = 50x + 75

isolate for x:

65x - 50x = 75
15x = 75
x = 5

therefore it will take 5 hours for each to cost the same. you should call Abe for any task more than 5 hours because it will be cheaper and you should call the Plumbing Service for any task less than 5 hours because it will be cheaper.

Opposite angles in a cyclic quadrilateral add up to 180°