Solving Linear Equations

A fitness club opens with 80 members. Each month the membership increases by 15 members. Which equation represents the relationship between the number of months the club has been opened, x, and the total fitness club membership, y?

• y=15x
• y=15x+80
• y=x+15
• y=80x+15

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat.  Write an equation for C, the total cost, to rent the boat for h hours.

• h = 2C + 15
• C = 15h + 2
• h = 15C + 2
• C = 2h + 15

The Roaming Cell Phone Company charges $15.00 per month plus $0.20 per minute of airtime usage.  If Juanita uses x minutes of airtime, what is an equation that can be used to determine her monthly cell phone bill (C)?

• C = 15 + 0.20x
• C =15 (0.20x)
• C = 15 + x + 0.20
• C = 0.20 + 15x

Bob's Plumbing charges $15 per hour plus a service fee of $40 for coming out to your house. Which equation models this situation?

• y = 15x + 40

• y = 40x + 15

• y = 15x

• y = 15x - 40

Dexter's Gym charges a one-time registration fee of $40 and $20 each month. The total fee after x months is $340. Which equation models this situation?

• 40x + 20 = 340

• 20x + 40 = 340

• 20x - 40 = 340

• 20 + 340 = 40x

Dexter's Gym charges a one-time registration fee of $40 and $20 each month. The total fee after x months is $340. How many months was this person a member?

Evan is going to the 50th state fair this weekend. It costs $10 to enter and each ride is $2. Create a linear function that could be used to determine how many "x" rides Evan can go on.

What does the variable "y" represent?

• the number of rides he goes on

• the total cost of going to the fair

A plumber charges $50 to make a house call. He also charges $25 per hour for labor.

How much would it cost for 2.5 hours of labor?

• $100

• 4.50

• $112.50

• $65.00

• $123.45

How can we solve 5x - 14 = 8x + 4?

• STAT, EDIT

• 1. Y1= 5x-14

  2. Y2= 8x+4

  3. Graph and find the intersection

• 1. Put all variable terms on one side

  2. Put all constant terms on the opposite side.

  3. Divide both sides by the coefficient.

• Just guess

5x - 14 = 8x + 4

• x = 6
• x = -6
• x = -18/13
• x = 10/3