3-8 RLE 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

The local service center advertises that it charges a flat fee of $50 plus $8 per mile to tow a vehicle. Write an equation that represents the total cost (C) of a service for m miles of towing.

• y = 8x + 50

• C = 50m +8

• y = 50x + 8

• C = 8m + 50

A camp charges families a fee of $625 per month for one child and a certain amount more per month for each additional child. Use the graph to write an equation in slope-intercept form to represent the amount a family with x additional children would pay.

• y = 625x + 225
• y = 225x 
• y = 225x + 625
• y =  625

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

Jenny went to the sale at Kohl's last weekend.  
T-shirts were on sale for $15 each and hoodies were on sale for $20 each.  If she spent $150 total, write an equation to represent this situation.  

• 20x + 15 = y 
• 35x = y 
• 15x + 20y = 150 
• 150 - 20x = 15y 

The booster club made $708 on homecoming T-shirt sells. Small t-shirts cost $12 while large t-shirts cost $14. If x is small t-shirts and y is large t-shirts, what equation represents this.

• 12x + 14y = 708

• 14x + 12y = 708

• 708x + 14y = 12

• 12x + 708y = 14

Juan is selling shirts for a fund raiser. Short sleeve shirts (x) cost $15 each and long sleeve shirts (y) cost $20 each. His goal is to raise $400 so his club can go on a field trip. Juan uses the equation below to represent his situation.

15x + 20y = 400

What does the x-intercept represent?

• The number of short sleeve shirts Juan must sell if he does not sell any long sleeve shirts.

• The number of long sleeve shirts Juan must sell if he does not sell any short sleeve shirts.

• The lowest number of shirts Juan could possibly sell.

• The total number of short sleeve and long sleeve shirts Juan sells.

A football team scores 63 points. All of the points come from field goals (x) worth 3 points and touchdowns (y) worth 7 points. Write an equation in standard form that represents this situation. Then convert it to slope-intercept form. Select the correct standard form and slope-intercept form.

• 3x + 7y = 63

• 7x + 3y = 63