<h3>The equation in slope intercept form that models the cost of the work performed is: y = 78x + 79</h3><h3>It costs $ 547 if the plumber works for 6 hours</h3>
<em><u>Solution:</u></em>
Let "y" be the total cost of the house call plus labor
Let "x" be the number of hours worked
A plumber charges a flat rate of $79 to make a house call and charges $78 for labor
<em><u>The slope intercept form is given as:</u></em>
y = mx + c
Therefore,
total cost of the house call plus labor = 79 + 78(number of hours worked)
y = 78x + 79
Thus the equation is found
<em><u>How much does it cost if the plumber works for 6 hours?</u></em>
Substitute x = 6 hours
y = 78(6) + 79
y = 468 + 79
y = 547
Thus it costs $ 547 if the plumber works for 6 hours
