Question

1. one plumber charges a trip fee of $135 and an hourly rate of $105. another plumber charges a trip fee of $195 and an hourly rate of $90. this scenario can be modelled by:

$c = 135 + 105t$ ①
$c = 195 + 90t$ ②
what is the meaning, in context, of $(4, 555)$? emerging

Explanation:

The ordered pair \((t, c)\) represents time in hours and total cost in dollars. Substitute \(t=4\) into both cost equations:

1. For the first plumber: \(c = 135 + 105(4) = 135 + 420 = 555\)
2. For the second plumber: \(c = 195 + 90(4) = 195 + 360 = 555\)

This pair is the intersection of the two cost functions, meaning at 4 hours of work, both plumbers charge the same total cost of $555.

Answer:

The ordered pair (4, 555) means that when 4 hours of plumbing work are done, both plumbers charge a total cost of $555.