Applications
Site: | St. Louis |
Course: | Michigan Algebra I Sept. 2012 |
Book: | Applications |
Printed by: | Guest user |
Date: | Thursday, November 21, 2024, 12:44 PM |
Description
Problem 1
Marcel rented a moving truck for the day. Marcel remembers that the rental truck company charges $40 per day, but has forgotten how many cents per mile he is charged. Marcel drives 46 miles and the final amount of the bill (before tax) is $63. What is the amount per mile the truck rental company charges? Write an equation in point-slope form that describes this situation. How much would it cost to rent this truck if Marcel drove 220 miles?
Answer 1
Step 1. Define the variables.
x = distance in miles
y = cost of the rental truck in dollars
Step 2. Determine the y-intercept and a point.
The y-intercept is given, the cost of the truck with 0 miles is $40 so the y-intercept is (0, 40).
Marcel pays $63 for 46 miles, representing the point (46, 63).
Step 3. Use the y-intercept (b) and the given point (x, y) to determine the function rule.
Step 4. Substitute values for m and a point into
Step 5. To answer the question about the cost of 220 miles, substitute x = 220.
Problem 2
Anne got a job selling window shades. She receives a monthly base salary and a $6 commission for each window shade she sells. At the end of the month, she adds up her sales and she figures out that she sold 200 window shades. She made $2500. Write an equation in point-slope form that describes this situation. How much is Anne's monthly base salary?
Answer 2
Step 1. Define the variables.
x = number of window shades sold
y = Anne's monthly salary in dollars
Step 2. Determine the slope and a point.
Anne gets $6 for each shade, so the slope = 6 dollars/shade.
She sold 200 shades and made $2500, representing the point (200, 2500).
Step 3. Determine the function rule by using the point-slope form.
Step 4. Determine Anne's base salary by substituting x = 0.
$1300 is Anne's base salary.
Problem 3
Nadia has $200 in her savings account. She gets a job that pays $7.50 per hour and she deposits all her earnings in her savings account. Write the equation describing this problem in slope-intercept form. How many hours would Nadia need to work to have $500 in her account?
Answer 3
Step 1. Define the variables.
y = amount of money in Nadia's savings account
x = number of hours
Step 2. Determine the y-intercept and slope.
Nadia has $200 in her savings account, so b = 200.
She has a job that pays $7.50 per hour, so m = 7.50.
Step 3. Determine the function rule using the slope-intercept form.
y = 7.5x + 200
Step 4. Substitute and solve to determine the number of hours Nadia needs to work to earn $500.
500 = 7.5x + 200
7.5x = 300
x = 40
Nadia needs to work 40 hours to earn $500.
Problem 4
Nimitha buys fruit at her local farmer's market. This Saturday, oranges cost $2 per pound and cherries cost $3 per pound. She has $12 to spend on fruit. Write an equation in standard form that describes this situation. If she buys 4 pounds of oranges, how many pounds of cherries can she buy?
Answer 4
Step 1. Define the variables.
x = pounds of oranges
y = pounds of cherries
Step 2. Write an equation.
Since there are two rates, neither can be the slope alone.
Therefore, the equation that describes this situation is: 2x + 3y = 12
Step 3. Substitute 4 for x and solve for y.
Nimitha can buy pounds of cherries.
Problem 5
Jethro skateboards part of the way to school and walks for the rest of the way. He can skateboard at 7 miles per hour and he can walk at 3 miles per hour. The distance to school is 6 miles. Write an equation that describes this situation. If Jethro skateboards for half an hour, how long does he need to walk to get to school?
Answer 5
Step 1. Define the variables.
x = hours Jethro skateboards
y = hours Jethro walks
Step 2. Write an equation.
Since there are two rates, neither can be the slope alone.
The equation that describes this situation is: 7x + 3y = 6
Step 3. Substitute 0.5 for x and solve for y.
Jethro must walk of an hour.
Practice
Miles to Your Destination Worksheet
*Note: If Google Docs displays "Sorry, we were unable to retrieve the document for viewing," refresh your browser.
Answer Key
Miles to Your Destination Answer Key
*Note: If Google Docs displays "Sorry, we were unable to retrieve the document for viewing," refresh your browser.
Sources
Embracing Mathematics, Assessment & Technology in High Schools; A Michigan Mathematics & Science Partnership Grant Project
Gloag Anne and Andrew, "Writing Linear Equations", CK-12 Foundation's Algebra FlexBook, December 9, 2009, http://www.ck12.org/flexr/flexbook/738/