Interpret Linear Equations in Context

A T-shirt design company charges your team a startup fee of $25 to create the team's design. Each t-shirt printed with your design costs an additional $8. The equation for this situation is y = 8x + 25. Interpret the y-intercept in context.

• The additional fee of $8.

• The starting fee of $25.

• The additional fee of $25.

• The starting fee of $8.

The demand for a certain product is given by the equation y = 4,500 - 450p, where p is the price of the product and y represents the number of units in demand.  Interpret the slope in context.

• For each dollar the price increases, demand decreases by 450 units.

• For each dollar the price increases, demand increases by 450 units.

• For each dollar the price increases, demand decreases by 4.500 units.

• For each dollar the price decreases, demand decreases by 4.500 units.

A company developed the linear model to help budget annual expenses over time.  In the model, x represents the number of years after 2009, and y represents the expense budget in dollars. Interpret the y-intercept.
y = 189,785 + 37,896x

• The company's expense budget for 2009 was $37,896.

• The company's expense budget for 2008 was $189,785.

• The company's expense budget for 2009 was $189,785.

• The company's expense budget for 2008 was $37,896.

A restaurant investigated the correlation between the prices and the number of customers.  The linear model below represents this situation, where x is the average meal price (in dollars), and y is the number of daily customers.  Interpret the slope.
y = 437 - 18x

• The average price per meal is $18.

• The average number of daily customers is 18.

• If the average meal price decreases by a dollar, the number of daily customers decreases by 18.

• If the average meal price increases by $1, the number of daily customers decreases by 18.

At the beginning of the summer, Jenna had saved $141.  To earn money of the summer, she is working part time at the local community center.  She will earn $32 per day of work.  If x represents the number of days she works, which of the following equations represents how much money she will have, including her savings?

• y = 141-32x

• y = x + 141

• y = 32x + 141

• y = 141x + 32

A strong cold front blew through during the night.  The temperature outside began to drop rapidly.  The graph shows the temperature at each hour after the cold front blew through.  What is the rate of change of the graph?

• 2.5°F per hour

• 0.2°F per hour

• -0.2°F per hour

• -2.5°F per hour

Kiki wants to rent a bounce house for her daughter's party.  The cost, y, to rent the bounce house for the number of hours, x, is shown in the table.  The rate per hour for the bounce house is which of the following?

• $65

• $55

• $130

• $185

On average, Matt's manufacturing company produces 130 units in 5 working days and 650 units in 25 working days.  In a linear model of this situation, which of the following statements applies?

• An additional day of production is associated with 26 units.

• An additional day of production is associated with 39 units.

• An additional day of production is associated with 7.8 units.

• An additional day of production is associated with 104 units.

Several years ago, Conner bought an antique clock.  Since then, it has increased in value.  If x represents the number of years he has owned the clock, and y represents the value of the clock (in dollars), which of the following situations in represented by the graph?

• Dave bought the clock for $300 and each year the value increased by $125.  

• Dave bought the clock for $300 and each year the value increased by $50.  

• Dave bought the clock for $300 and each year the value increased by $200.

• Dave bought the clock for $300 and each year the value increased by $100.

Stephanie planted a home garden.  She planted 2 rows of tomatoes with 4 tomato plants in each row.  She also planted squash in rows of 6 plants each.  If x represents the number of rows of squash she planted, which of the following equations can be used to find the total number of plants Stephanie planted in her home garden?

• y = 6x + 6

• y = 8x + 6

• y = 7x + 6

• y = 6x + 8