Download Worksheet 7.3 Graphing 3 ways Name

College Prep Algebra
Homework
Name: ________________
Date: _________________
HW Lesson 3.7B: Applications of Linear Equations
Write and solve a linear equation for each of the following application problems.
1. Ms. Adams has 32 ounces of water in a bottle. She can drink 5 ounces an hour.
a. How much water does she have left after n hours?
______________________
b. How many hours will it take her to finish the bottle of water?
___________
2. At a party store, helium balloons cost 79 cents each and a box of favors costs $11.95.
You have $40 to spend and you need two boxes of favors. How many balloons can you
buy? There is no sales tax.
___________
3. A chemist has solutions of hydrochloric acid in two different concentrations. One solution
has 10 moles per liter; the other has 2.5 moles per liter. She mixes x liters of the first
solution and y liters of the second solution.
a. How many moles of acid are in x liters of the first solution?
___________
b. How many moles of acid are in y liters of the second solution?
___________
c. How many moles of acid are in the mixture?
_____________________
d. The chemist wants to have 6 moles of acid in the final mixture. She uses 1 liter of the
second solution. How many liters of the first solution should she use?
___________
4. Card Carriers charges $36 to print 1200 business cards and $56 for 2700 cards. Assume
the relationship between the price and the number of business cards is linear.
a. Write an equation giving price as a function of the number of cards printed.
_____________________
b. Find the set-up cost (the cost of printing 0 cards).
___________
c. Find the cost of printing 6000 cards.
___________
5. The temperature of an oven is 350  F before being turned off. The temperature drops at
a constant rate to 190  F in 20 minutes.
a. Convert the rate of change to  F per minute.
___________
b. Find how long it takes for the oven to cool to 150  F.
___________
6. At a produce market, Granny Smith apples are $0.75 a pound and Red Delicious apples
are $0.95 a pound. Jim has $9 and buys 3 pounds of Granny Smith apples. Round
answers to the nearest pound.
a. How many pounds of Red Delicious apples can he buy?
___________
b. If the price of each kind of apple increases $0.11 per pound, how many pounds of Red
delicious apples can he buy?
___________
7. A chemist mixed A ounces of a 30% chlorine solution with B ounces of a 40% chlorine
solution. The final mixture contained 18 ounces of chlorine. Write an expression to model
this situation.
______________________
8. Last week, Mr. Chinn sold $20,000 worth of newspaper advertisements and earned $800.
The week before, he sold $26,000 worth of advertisements and earned $860. Assume the
relationship between Mr. Chinn’s weekly earnings and the value of the advertisements he
sells is linear.
a. Write an equation giving Mr. Chinn’s weekly earnings as a function of the value of the
advertisements he sells.
______________________
b. In this situation, what do the slope and y-intercept mean?
c. If in one week, Mr. Chinn sells $30,000 worth of advertisements, how much will he
earn?
___________
9. Mr. Reyes bought 5 pounds of coffee. On the average, he uses one-fifth of a pound a
week.
a. Write an equation relating the pounds of coffee c he has left after w weeks.
______________________
b. During what week will he likely run out of coffee?
___________
10. Helene bought L 74-minute recordable CDs at $0.58 each and M 80-minute recordable
CDs at $0.95 each. Suppose she spent $12.40 and bought ten 80-minute CDs. How
many 74-minute CDs did she buy?
___________
In 11 and 12, consider the following information. On a quiz show, 20 points are given for
correct answers to regular questions and 50 points are given for correct answers to bonus
questions.
11. If a contestant answers 5 regular questions correctly and 7 bonus questions correctly,
how many points does she have?
___________
12. Suppose a contestant earned 650 points.
a. If she answered 13 bonus questions correctly, how many regular questions did she
answer correctly?
___________
b. If she answered 25 regular questions correctly, how many bonus questions did she
answer correctly?
___________
13. The Kelvin temperature scale is often used by scientists who work with very cold
materials. Water freezes at 32  F or 273 K. Water boils at 212  F or 373 K. What
Fahrenheit temperature corresponds to 0 K?
___________