Equations from Scenarios

Which of the following situations could be described by the equation:

y= -25x+120

• There are 120 people in the football stadium, and 25 more are entering each hour.

• A plumber charges $25 for a house call and $120 per hour.

• A teacher has 120 students. Her third period has 25 students

• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

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

An electrician charges $25 to make a house call, plus $40 for every hour of work. Which equation shows how to find C, the total cost for having the electrician work for h hours?

• C = 40h+25

• C = 65+h

• C = 65h

• C = 25h +40

A 9-inch candle burns at a rate of 1.5 inches an hour. Which equation represents the relationship between y, the height of the candle in inches, and x, the number of hours the candle burns?

• y = 1.5x + 9

• y = -1.5x+9

• y = 1.5 - 9x

• y = 9x + 1.5

A tree is 16.35 inches tall and will grow at a rate of 4.2 inches every month.

• y = 16.35n + 4.2

• y = 4.2n + 16.35

• y = 4.2n - 16.35

• y = 16.35n

Which of the following situations can be represented by y=0.55n+10

• The total cost at a store if you buy one book for $10 and n bookmarks that cost $0.55 each.

• The total cost of 10 bags of chips that cost $0.55 each.

• The height of a tree after n day that was 10feet tall and it grew 55 feet a day.

• Not here

Lee charges $3 for a basket and $2.50 for each pound of fruit picked at the orchard. Write an equation in y = mx + b form for the total cost of x pounds of fruit from the orchard.

• y = 3x + 2.5
• y = 2.50x + 3
• y = 2.50x 
• y = 3x + 2.50

A driving range charges $4 to rent a golf club plus $2.75 for every bucket of golf balls you hit. Write an equation that shows the total cost c of hitting b buckets of golf balls.

• c = 2.75b + 4
• c = 2.75b
• c =  4b- 2.75
• c = 2.75b - 4

For lunch, Amanda had a hamburger and potato chips. The hamburger totaled 325 calories and each chip had 12 calories. Write a liner equation to represent the situation.

• y = 12 + 325
• y = 12x  + 325
• y = 325 - 12x
• y = 325x + 12

Austin's Dad started a savings account for him by putting in $50 to start with. Every month then Austin is to put in $10.

• y=50x+10

• y=1/50 x+10

• y=10x+50

• y=1/10 x+50