Point-Slope Form: Find Slope & Write Cost Equations

A car rental company charges a flat fee of $50 plus $20 for each day the car is rented. Write the equation in point-slope form using the point (1, 70) and identify the slope.

• C - 70 = 20(d - 1) with a slope of 20.

• C - 50 = 20(d - 1) with a slope of 50.

• C - 70 = 20(d - 2) with a slope of 20.

• C - 70 = 30(d - 1) with a slope of 30.

A local gym has a membership fee of $30 and charges $15 per class. If a member attends 4 classes, what is the point-slope form of the cost equation using the point (4, 90)?

• y - 90 = 15(x - 5)

• y - 90 = 15(x - 4)

• y - 90 = 20(x - 4)

• y - 90 = 10(x - 4)

A bakery sells cupcakes for $3 each and has a fixed cost of $20 for supplies. Write the point-slope form of the cost equation using the point (10, 50) and identify the slope.

• y - 50 = 3(x - 10) and the slope is 3.

• y - 50 = 2(x - 10) and the slope is 2.

• y - 50 = 4(x - 10) and the slope is 4.

• y - 50 = 3(x - 5) and the slope is 3.

A taxi service charges a base fare of $5 plus $2 per mile. If a ride covers 3 miles, express the cost in point-slope form using the point (3, 11) and identify the slope.

• y - 11 = 1(x - 3), slope = 1

• y - 11 = 3(x - 3), slope = 3

• y - 11 = 2(x - 2), slope = 2

• y - 11 = 2(x - 3), slope = 2

A phone plan costs $40 per month plus $0.10 per text message. If a user sends 100 messages, write the equation in point-slope form using the point (100, 50) and identify the slope.

• y - 50 = 0.20(x - 100), slope = 0.20

• y - 50 = 0.10(x - 100), slope = 0.10

• y - 50 = 0.10(x - 50), slope = 0.10

• y - 50 = 0.05(x - 100), slope = 0.05

A concert venue charges $25 for a ticket and $10 for parking. If a group of 5 people attends, express the total cost in point-slope form using the point (5, 75) and identify the slope.

• y - 75 = 15(x - 5)

• y - 75 = 10(x - 5)

• y - 75 = 30(x - 5)

• y - 75 = 25(x - 5)

A school charges $200 for a field trip plus $15 per student. If 10 students sign up, write the equation in point-slope form using the point (10, 350) and identify the slope.

• y - 350 = 20(x - 10), slope = 20

• y - 200 = 15(x - 10), slope = 15

• y - 350 = 15(x - 10), slope = 15

• y - 350 = 10(x - 10), slope = 10

A delivery service charges a flat fee of $10 plus $1.50 per mile. If a delivery is made over 5 miles, express the cost in point-slope form using the point (5, 17.5) and identify the slope.

• C - 20 = 1.5(m - 5), slope = 1.5

• C - 10 = 1.5(m - 5), slope = 1.5

• C - 17.5 = 1.5(m - 5), slope = 1.5

• C - 17.5 = 2(m - 5), slope = 2

A subscription box service charges $25 per month plus $5 for shipping. If a customer subscribes for 3 months, write the equation in point-slope form using the point (3, 80) and identify the slope.

• y - 80 = 30(x - 3) with a slope of 30.

• y - 80 = 20(x - 3) with a slope of 20.

• y - 80 = 25(x - 2) with a slope of 25.

• y - 80 = 25(x - 3) with a slope of 25.

A landscaping company charges $100 for a service plus $20 for each additional hour worked. If a job takes 4 hours, express the total cost in point-slope form using the point (4, 180) and identify the slope.

• y - 180 = 25(x - 4), slope = 25

• y - 180 = 10(x - 4), slope = 10

• y - 100 = 20(x - 4), slope = 20

• y - 180 = 20(x - 4), slope = 20