Real World Applications of Linear Equations

Which situation below is representative of y-intercept?

• putting $300 a month into savings
• buying $30 worth of supplies for a lemonade stand
• Spending $3 per ride at the fair
• Paying $2 for parking every day

Sonya has $40 in her lunch account and pays $2 each day to eat lunch.  Which equation can be used to find the amount of money Sonya has left on her account after x days?

• y = 40 + 2x
• y = 40 - 2x
• y = 2 + 40x
• y = 2 - 40x

Amber's savings account had a balance of $350 rolled over from the previous year. She set it up for $50 to be drafted out of her checking account and into her savings account every month. What information in this problem represents the y-intercept?

• 350
• 50
• -50
• -350

Which equation shows the number of bottles left after x days?
A family buys a case of water with 48 bottles and drinks 5 bottles per day.

• y = 48x + 5
• y = -5 + 48x
• y = -5x - 48
• y = 48 - 5x

Lin is tracking the progress of her plant’s growth. Today the plant is 5 cm high. The plant grows 1.5 cm per day. 
What will the height of the plant be after 20 days? 

• 25
• 30
• 35
• 40

At a pet store, it costs $5 to wash a cat and $7.50 to wash a dog.  Last week, the store made $60 from washing cats and dogs.  If 6 cats were washed, write and solve a linear equation to find how many dogs were washed.

• 2 dogs
• 3 dogs
• 4 dogs
• not enough information

 At a school play, children’s tickets cost $3 each and adult tickets cost $7 each. The total amount of money earned from ticket sales equals $210. Write a linear model that relates the number of children’s tickets sold to the number of adult tickets sold. Let x = the number of children’s tickets sold and y = the number of adult tickets sold

• y=10x+210
• 7x+3y=210
• y=7x+210
• 3x+7y=210

Would you write a linear equation to model the following situation in slope-intercept form or standard form? 
The price of a large cheese pizza is $5.95 plus an additional $0.75 per topping. 

• slope-intercept
• standard form

Would you write a linear equation to model the following situation in slope-intercept form or standard form? 
Mrs. Harris is going to the movies. She spends $10 per ticket and $5 per bucket of popcorn. She only wants to spend $50. 

• Slope-intercept
• Standard form

Write the equation in Standard Form.
A store sells t-shirts for $12 each and sweatshirts for $15 each. You plan to spend $120 on t-shirts and sweatshirts.

• 2x + 5y = 120
• 12x + 15y = 120
• 12 + 15y = 2x
• 12x + 15 = 120