Interpreting linear functions

Quinn returned home one summer's day to find it sweat-inducingly hot! He turned the air conditioner on, and the room's temperature began decreasing at a constant rate. This is the formula for the room's temperature R (measured in degrees Celsius) as a function of time t (measured in minutes): R(t)=42-0.7t How many degrees celsius did the temperature drop by each minute?

0.7

A lake near the Arctic Circle is covered by a thick sheet of ice during the cold winter months. When spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. This is the formula for the ice sheet's thickness S (measured in meters) as a function of time t (measured in weeks): S(t)=-0.25t+4 Every 6 weeks, the sheet's thickness decreases by how many meters?

1.5

A big cruise ship drops anchor off the Caribbean island of Antigua. The heavy anchor drops into the water at a constant rate. This is the formula for the anchor's elevation relative to the water's surface E (measured in meters) as a function of time t (measured in seconds): E(t)=-2.4t+75 Every 5 seconds, how many more meters is the anchor dropped?

12

Simba Travel Agency arranges trips for climbing Mount Kilimanjaro. For each trip, they charge an initial fee in addition to a certain amount for each vertical meter climbed. This is the formula for the fee of a trip F (measured in dollars) as a function of the vertical distance climbed d (measured in meters): F(d)=110+0.12d If a group decides to climb up an additional 100 meters, how much will their trips cost increase by?

12

d = h + 3 The variable h represents the number of hours worked, and the variable d represents the amount of dough prepared. How much dough did Ezra prepare if he worked for 9 hours?

12

A charity organization is having a fundraiser. Before they sell any tickets to this fundraiser, they have to spend some money to take care of necessary production costs. They are selling tickets at a fixed price. This is the formula for the net profit from the fundraiser P (measured in dollars) as a function of the number of tickets sold n: P(n)=70n-1500 How much does the fundraiser cost to produce?

1500

h = 6t + 4 The variable t represents the number of years Sanjay since his last haircut, and the variable h represents the hair length in centimeters. Sanjay last got his hair cut 2 years ago. How long is it now?

16

Temperature can be measured in two different common units: degrees Celsius and degrees Fahrenheit. This is the formula for the temperature in degrees Fahrenheit F as a function of the temperature in degrees Celsius C: F(C)=32+1.8C When the temperature rises by 10 degrees Celsius it can also be said that it rises by how many degrees Fahrenheit?

18

s = d + 1 The variable d represents the number of days he spends on vacation, and the variable s represents the total number of souvenirs he buys. How many days will Logan have to spend on vacation before he will have bought a total of 19 souvenirs?

18

d = 19t The variable t represents the number of workbooks bought by the school, and the variable d represents the total cost of those workbooks. How much would it cost Newport Middle School to buy a total of 1 workbook?

19

d = 3a + 4 The variable a represents the number of attendees, and the variable d represents the cost in dollars. If there are 5 attendees, how much will Kelly's graduation picnic cost?

19

j = 5d + 14 The variable d represents the number of days spent making jam, and the variable j represents the amount of jam jarred. How much jam did Henry jar if he spent 1 day making jam?

19

d = c The variable c represents the number of cups sold, and the variable d represents earnings. How many cups of lemonade does Owen need to sell in all to earn $4?

4

h = 2a + 10 The variable a represents the age of the sapling in years, and the variable h represents the height of the sapling in inches. How old was the sapling when it was 20 inches tall?

5

Agent Hunt is transferring classified files from the CIA mainframe into his flash drive. This is the formula for the size of the files on Agent Hunt's drive S (measured in megabytes) as a function of time t (measured in seconds): S(t)=5t+45 Every 10 seconds, how many more megabytes are transferred into the drive?

50

Anumeha is mowing lawns for a summer job. For every mowing job, she charges an initial fee in addition to a constant fee for each hour of work. This is the formula for her fee for a single job F (measured in dollars) as a function of the number of hours t it took her to complete it: F(t)=6+12t What is her initial fee?

6

Mr. Mole left his burrow that lies below the ground and started digging his way deeper into the ground, descending at a constant rate. This is the formula for Mr. Mole's altitude relative to the ground A (measured in meters) as a function of time t (measured in minutes): A(t)=-2.3t-7 How many meters below the ground is moles burrow?

7