The linear function graphed below represents Brenda’s monthly cell phone bill based on the number of hours she uses. What is her hourly rate?

A graph titled Brenda's Monthly Cell Phone Bill has hours used on the x-axis and cell phone bill (dollars) on the y-axis. Points plotted are (1, 27), (2, 39), and (3, 51).
$12 per hour
$15 per hour
$27 per hour
$39 per hour

Question

The linear function graphed below represents Brenda’s monthly cell phone bill based on the number of hours she uses. What is her hourly rate?

A graph titled Brenda's Monthly Cell Phone Bill has hours used on the x-axis and cell phone bill (dollars) on the y-axis. Points plotted are (1, 27), (2, 39), and (3, 51).
$12 per hour
$15 per hour
$27 per hour
$39 per hour

jasmine1112 · Answer

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Mercury · Answer

the hours are on the x-axis, and the bill is on the y-axis

therefore, the points (1, 27), (2, 39) mean that, for 1 hour she was charged $27 and for 2 hours she was charged $39

find the difference between the two dollar amounts, to find the charge per hour