Question

Sanjay consulted three electricians about upgrading the wiring in his home. Each electrician uses a linear formula that incorporates a flat base fee and an hourly rate to determine the cost of service. Those formulas are shown in the table.

Repair Cost Formulas
Electrician
Cost in y dollars for an x-hour service
1
y = 25 x + 30
2
y = 30 x + 25
3
y = 25 x + 20

Which statement is best supported by the table?
Each electrician charges a different hourly rate.
Each electrician charges a different base fee.
All three electricians charge the same hourly rate.
All three electricians charge the same base fee.

Answer 1

b.Each electrician charges a different base fee:

Explanation:

Each of the equations has two parts:

1- base fee that is independent of any variable (this would be the number that has no variable next to it)

2- an hourly rate depending on the number of hours x (this would be the number that has an x next to it)

For the first electrician:

y = 25x + 30

base fee = $30

hourly rate = $25

For the second electrician:

y = 30x + 25

base fee = $25

hourly rate = $30

For the third electrician:

y = 25x + 20

base fee = $20

hourly rate = $25

Now, let's check the choices:

a.Each electrician charges a different hourly rate:

This is incorrect as electricians 1 and 3 charge the same hourly rate ($25)

b.Each electrician charges a different base fee:

This is correct as all three base fees are different ($30, $20 and $25)

c.All three electricians charge the same hourly rate:

This is incorrect as electrician 2 has a different hourly rate

d. All three electricians charge the same base fee:

This is incorrect as the base fees for the three electricians are different ($30, $25 and $20)

Answer 2

Answer: B: each electrician charges a different base fee

Step-by-step explanation: