Real World Problems Writing Linear Functions

After paying $5.12 for a salad, Kamauri has $27.10. How much money did he have before buying the salad?

• n + $5.12 = $27.10

• n - $5.12 = $27.10

• n - $5.12 = -$27.10

• $5.12 - n = $27.10

Which equation would describe "two times a number plus five equals 15"?

• x + 5 = 15

• 2x + 5=15

• x + 2(5) = 15

• 2(x + 5) = 15

For a field trip 4 students rode in cars and the rest filled nine buses. How many students were in each bus if 472 students were on the trip?

• 4x=472

• 9x=472

• 4+9x=472

• 4+x=472

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)  

• A

• B

• C

• D

Which situation can be represented by y=12x-4?
*Hint: Pay attention to your sign for your y-intercept*

• The number of eggs, y, in x dozen eggs for sale after 4 dozen eggs are sold

• The cost, y, of buying x movie tickets that sell for $4 each

• The cost, y, after a $4 discount, of buying x T-shirts that sell for $12 each

• The number of inches, y, in an x-foot-tall tree after cutting off 4 feet

You plan to go snowboarding. The resort charges $15 an hour in addition to $25 to rent a board. Write an equation that represents the cost to go snowboarding for the day.

• y=15x-25

• 15x+25y=100

• 25x+y=15

• y=15x+25

Is the graph linear, exponential or neither?

• Linear

• Exponential

• Neither

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

• y = 30 + 12.5x 

• y = 12.5 + 30

• y = 12.5 + 30x