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Geeta, Richard, and Steve are all computer repair technicians. The equation, graph, and table shown represent the amount of pay (p) in dollars they each receive as a function of the number of hours (h) a computer repair takes.

Study each of the functions (attached image) and then answer the following questions.


-Who earns the most per hour, Geeta, Richard, or Steve? Explain how you found your answer.


-Which technician(s) have an equation for their pay with the y-intercept at a point other than (0,0)? Explain what the y-intercept(s) mean(s) in terms of this scenario.

Geeta, Richard, and Steve are all computer repair technicians. The equation, graph-example-1
User Jaswrks
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1 Answer

3 votes

Answer:

Steve

Greta & Richard

Explanation:

Greta:

p = 75 + 45h

The equation of her pay is:

p = 45h + 75

Compare that with

y = mx + b

Here, m = 45, and b = 75.

m, the slope, is the hourly rate Greta charges.

b, the y-intercept, is the initial charge.

In other words, if you call Greta, she charges $75 just to go there before she works any time at all. Then she charges $45 per hour.

Richard:

Look in the graph. The y-intercept is (0, 50). That means b = 50.

Now we calculate the slope using 2 points.

(0, 50), (1, 80)

slope = (difference in y)/(difference in x)

slope = m = (80 - 50)/(1 - 0) = 30/1 = 30

m = slope = 30.

Since the slope is 30, and the y-intercept is 50, that means that Richard charges $30 per hour and an initial fee of $50 just to go there.

p = 30h + 50

Steve:

Take two lines of information from Steve's table:

(3, 165), (5, 275)

Let's find the equation of a line through those two points.

m = slope = (difference in y)/(difference in x)

m = (275 - 165)/(5 - 3) = 110/2 = 55

y = mx + b

165 = 55(3) + b

165 = 165 + b

b = 0

y = 55x

p = 55h

The slope of Richard's equation is 55, so Richard charges $55 per hour. For Richard, b = 0. Since the y-intercept is zero, that means Richard does not charge an initial fee. With Richard, his total pay is only from the number of hours he works.

Now we can answer the questions.

-Who earns the most per hour, Geeta, Richard, or Steve? Explain how you found your answer.

Greta: $45/hour

Richard: $30/hour

Steve: $55/hour

Answer: Steve

-Which technician(s) have an equation for their pay with the y-intercept at a point other than (0,0)? Explain what the y-intercept(s) mean(s) in terms of this scenario.

The equation of their pay are:

Greta: p = 45h + 75

Steve: p = 30h + 50

Steve: p = 55h

Answer: Greta at 75 and Richard at 50. This means they charge those amounts before they work any time. The fee for them to come to you is the y-intercept.

User Roman Romanov
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