Homework 9B

Q1: The following situation can be modeled by a linear function. make an equation for the linear function and use it to answer the given question. Be sure you clearly identify the independent and dependent variables. Then briefly discuss whether a linear model is reasonable for the situation described.

The price of a particular model car is

$19,000

today and rises with time at a constant rate of

$980

per year. How much will a new car of this model cost in

3.2

years?

Select the correct choice below and fill in the answer box to complete your choice.

(Simplify your answer.)

A.

The independent variable is time (t), in years, and the dependent variable is the price (p), in dollars. The linear function that models this situation is

p=enter your response here.

B.

The independent variable is the price (p), in dollars, and the dependent variable is time (t), in years. The linear function that models this situation is

t=enter your response here.

Q2: Question content area top

Part 1

Suppose your dog weighed

2.6

pounds at birth and weighed

14

pounds one year later. Based on these two data points, find a linear function that describes how weight varies with age. Use this function to predict your dog's weight at

4

and

11

years of age. Comment on the validity of this model.

Q3: Find the slope and the point containing the y-intercept. Then graph the equation.

y=4x3

Question content area bottom left

Part 1

What is the slope?

Q4: Use the slope and the point containing the y-intercept to graph the line.

y=7x3

Question content area bottom left

Part 1

What is the slope?

Homework 8B

Q1: Question content area top

Part 1

The number of cells in a tumor doubles every

2.5

months. If the tumor begins with a single cell, how many cells will there be after

2

years? after

4

years?

Question content area bottom

Part 1

How may cells will there be after

2

years?

Q2: Question content area top

Part 1

The current population of a threatened animal species is

1.8

million, but it is declining with a half-life of

25

years. How many animals will be left in

40

years? in

60

years?

Question content area bottom

Part 1

The population after

40

years will be

593,779593,779

animals.

(Round to the nearest whole number as needed.)

Part 2

The population after

60

years will be

33

animals.

Q3: A particular isotope has a half-life of

94

days. If you start with

1

kilogram of this isotope, how much will remain after

180

days? after

360

days?

Question content area bottom

Part 1

The remaining amount after

180

days will be

enter your response here

kilogram(s

Q4: A particular isotope has a half-life of

1900

years. If you start with

1

kilogram of this isotope, how much will remain after

1300

years? After

13,000

years?

Question content area bottom

Part 1

The remaining amount after

1300

years will be

enter your response here

kilogram(s).

.