Open Up, Math 8, Unit 4

A ________________ is a set of two or more equations that have the same variables.

• solution of a system
• elimination method
• system of equations
• table

What does the x represent in this situation?
Manny’s Music Rental charges a fee of $40 plus $25 per month to rent a saxophone. Sid’s Saxophones charges $25 plus $30 per month to rent the same saxophone.
y = 25x + 40
y = 30x + 25

• price of a saxophone
• rental fee
• total cost
• number of months

What is the slope and y-intercept of
y=2x-1

• Slope = -1
  y-int = 2
• Slope = 1
  y-int = -2
• Slope = 1/2
  y-int = -1
• Slope = 2/1
  y-int = -1

Solve for x: $-118=-5\left(4+7x\right)+7$  

•  $-5$  

•  $-9$  

•  $3$  

•  $-1$  

Solve for n: $5n+3=15+8n$  

•  $-3$  

•  $15$  

•  $-4$  

•  $8$  

Solve for n: $-3\left(n+8\right)-4=-40-n$  

•  $11$  

•  $6$  

•  $2$  

•  $1$  

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

Tags

CCSS.8.F.B.4

CCSS.HSF.LE.A.2

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

Tags

CCSS.6.EE.C.9

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

Tags

CCSS.HSF-BF.A.1A

A holiday meal cost $12.50 a person plus a delivery fee of $30. Which equation represents the amount a holiday meal costs(y), including delivery, for x people?

• y = 12.50 + 30x

• y = 30 + 12.50x

• y = 12.50 + 30

• 12.50x = 30

Tags

CCSS.6.EE.C.9