Writing Linear Functions using STAT Key

Jen charges $7.50 for every hour, h, she babysits. Write a function, f(h), to represent the total amount Jen would make babysitting h, hours.

• f(h) = 1h + 7.5

• y = 7.5x

• f(h) = 7.5h

• y = 8h + 7.5

Mr. Cook is saving money in an account. At the beginning of the year, he has $56 in savings and puts in another $4 per week. Write a function f(x) that models the total amount in the savings account after x, weeks.

• f(x) = 56 + 4x

• f(x) = 56x + 4

• y = 4x + 56

• y = -56 - 4x

Water is filling up a bathtub. After the first minute, there are 6 gallons in the tub and then after 2 minutes, there are 11 gallons. Write a linear equation, b(t) to represent the number of gallons in the tub after t, minutes.

• b(t) = 11t + 6

• b(t) = 6t + 11

• b(t) = 1t + 5

• b(t) = 5t + 1

When using the STAT key to write an equation, you ALWAYS need a __________!

• graph

• table

• y =

• None of the above

Mr. Keefe is walking away from a light pole at a rate of 4 feet per second. If Mr. Keefe starts at a distance of 6 feet from the light pole, write an equation to represent the total distance, D(s) he is away from the light pole after, s, seconds.

• D(s) = 4s + 6

• D(s) = -4s + 6

• y = 4x + 6

• y = -6s + 4

The temperature outside is currently 68°F and falling at a steady rate of 4 degrees every hour. Write a linear equation that relates the Fahrenheit temperature, F, to the time in hours, t, it has been falling.

• F = -4x + 68

• F(t) = -4t + 68

• F(t) = 4t + 68

• F(t) = 4x + 64

Kyle is starting an exercise program. The FIRST day he will spend 28 minutes on a treadmill. He will increase his time on the treadmill by 4 minutes each day. Write an equation for T(d), the time, in minutes, on the treadmill on day d.

• T(d) = 4d + 28

• T(d) = 4d + 24

• y = 28d + 4

• y = 24d + 4

The local football team won the championship several years ago, and since then, ticket prices have been increasing $15 per year. The year they won the championship, tickets were $30. Write a formula, t(n), that will model prices n years after they won the championship.

• t(n) = 15n + 30

• t(n) = 15n + 15

• t(n) = 30n + 15

• y = 15n + 15

A parachutist is 300 feet above the ground. After she open her parachute, she falls at a constant rate of 2 feet per second. Write an equation that gives her height, h(t) above the ground in terms of seconds, t.

• h(t) = 2t + 300

• h(t) = -2t + 298

• h(t) = - 298t + 2

• h(t) = 300 - 2t

Tanya is making homemade greeting cards. The data table below represents the amount she spends in dollars, f(x), in terms of the number of cards she makes, x. Write a linear function, f(x) that represents the data.

• f(x) = 4.5x + .75

• f(x) = .75x + 4.50

• f(x) = 4x + 7.5

• f(x) = 7.50x + 4