Solving word problems using the slope-intercept form is an essential skill in algebra, and it's used to model real-world situations. The slope-intercept form, y = mx + b, where m is the slope and b is the y-intercept, provides a powerful tool for solving linear equations.
What is Slope-Intercept Form?
The slope-intercept form is a way of expressing linear equations in a format that makes it easy to identify the slope (m) and the y-intercept (b). The slope represents the rate of change, while the y-intercept represents the point where the line crosses the y-axis.
Why Use Slope-Intercept Form?
Using the slope-intercept form to solve word problems offers several advantages. It allows you to easily identify the slope and y-intercept, making it simple to graph the line and understand the relationship between the variables. Additionally, the slope-intercept form is useful for solving systems of linear equations and for modeling real-world situations, such as cost-benefit analysis and motion problems.
Types of Slope-Intercept Form Word Problems
There are several types of word problems that can be solved using the slope-intercept form, including:
- Cost-benefit analysis: These problems involve finding the optimal solution based on the cost and benefit of different options.
- Motion problems: These problems involve finding the position or velocity of an object based on its initial position and velocity.
- Investment problems: These problems involve finding the return on investment based on the initial investment and interest rate.
Examples of Slope-Intercept Form Word Problems
Here are a few examples of slope-intercept form word problems:
- Example 1: Tom has been saving money for a new bike and has $120 in his savings account. He plans to save an additional $15 per week for the next few weeks. If he wants to buy a bike that costs $250, how many weeks will it take him to save enough money?
- Example 2: A company is producing a new product and wants to determine the cost of producing x units. The cost of producing the product is $500 plus $10 per unit. If the company wants to produce 100 units, what is the total cost?
- Example 3: A car rental company charges a base fee of $20 plus $0.25 per mile. If a customer rents a car for a day and drives 120 miles, what is the total cost?
Solving Slope-Intercept Form Word Problems
To solve slope-intercept form word problems, follow these steps:
- Read the problem carefully and identify the variables and the constants.
- Write an equation in slope-intercept form that represents the problem.
- Identify the slope and y-intercept from the equation.
- Use the slope and y-intercept to solve the problem.
Step-by-Step Solutions to Slope-Intercept Form Word Problems
Here are the step-by-step solutions to the examples above:
- Example 1:
- Let x be the number of weeks Tom saves money.
- Write an equation in slope-intercept form: y = 15x + 120.
- Identify the slope (m) and y-intercept (b): m = 15, b = 120.
- Solve the problem: Tom needs to save $250 - $120 = $130 more. Since he saves $15 per week, it will take him $130 / $15 = 8.67 weeks to save enough money.
- Example 2:
- Let x be the number of units produced.
- Write an equation in slope-intercept form: y = 10x + 500.
- Identify the slope (m) and y-intercept (b): m = 10, b = 500.
- Solve the problem: The total cost of producing 100 units is y = 10(100) + 500 = $1500.
- Example 3:
- Let x be the number of miles driven.
- Write an equation in slope-intercept form: y = 0.25x + 20.
- Identify the slope (m) and y-intercept (b): m = 0.25, b = 20.
- Solve the problem: The total cost of driving 120 miles is y = 0.25(120) + 20 = $50.
Practice Slope-Intercept Form Word Problems
Here are a few practice problems to help you improve your skills in solving slope-intercept form word problems:
- Problem 1: A bakery is producing a new type of bread and wants to determine the cost of producing x loaves. The cost of producing the bread is $200 plus $0.50 per loaf. If the bakery wants to produce 500 loaves, what is the total cost?
- Problem 2: A person is planning a road trip and wants to determine the cost of driving x miles. The cost of driving is $50 plus $0.25 per mile. If the person wants to drive 200 miles, what is the total cost?
- Problem 3: A company is producing a new product and wants to determine the revenue from selling x units. The revenue from selling the product is $10 per unit plus a fixed cost of $500. If the company wants to sell 1000 units, what is the total revenue?
Answers to Practice Slope-Intercept Form Word Problems
Here are the answers to the practice problems above:
- Problem 1: The total cost of producing 500 loaves is y = 0.50(500) + 200 = $350.
- Problem 2: The total cost of driving 200 miles is y = 0.25(200) + 50 = $100.
- Problem 3: The total revenue from selling 1000 units is y = 10(1000) + 500 = $10,500.
Conclusion
Solving slope-intercept form word problems is an essential skill in algebra, and it's used to model real-world situations. By following the steps outlined above and practicing with different types of problems, you can improve your skills in solving slope-intercept form word problems.
What is the slope-intercept form?
+The slope-intercept form is a way of expressing linear equations in a format that makes it easy to identify the slope (m) and the y-intercept (b).
Why is the slope-intercept form useful?
+The slope-intercept form is useful because it allows you to easily identify the slope and y-intercept, making it simple to graph the line and understand the relationship between the variables.
How do I solve slope-intercept form word problems?
+To solve slope-intercept form word problems, read the problem carefully, write an equation in slope-intercept form, identify the slope and y-intercept, and use the slope and y-intercept to solve the problem.
We hope this article has helped you understand how to solve slope-intercept form word problems. If you have any questions or need further clarification, please don't hesitate to ask.