Identifying The Incorrect Coordinate Pair In The Linear Equation Y=5x-15

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In the realm of mathematics, linear equations form the bedrock of countless concepts and applications. Understanding how to work with them, plot their graphs, and identify points that lie on the line is crucial. This article delves into a problem involving a linear equation and a table of coordinate pairs, challenging us to identify a miscalculation. Let's dissect the problem, explore the underlying principles, and pinpoint the error.

Decoding the Linear Equation and Coordinate Pairs

At the heart of the problem lies the linear equation y = 5x - 15. This equation represents a straight line when plotted on a coordinate plane. Each point on this line can be represented as a coordinate pair (x, y), where x is the horizontal coordinate and y is the vertical coordinate. The equation dictates the relationship between x and y for all points on the line.

Elliott has created a table of coordinate pairs for this equation:

x 0 3 5 8
y -15 0 10 15

The challenge is to determine if all the points in the table satisfy the equation y = 5x - 15. If a point doesn't fit the equation, it signifies a calculation error.

Verifying Coordinate Pairs: A Step-by-Step Approach

To determine which point, if any, Elliott calculated incorrectly, we need to substitute the x value of each coordinate pair into the equation y = 5x - 15 and check if the resulting y value matches the one in the table. This process involves simple arithmetic and a keen eye for detail.

Let's examine each point individually:

  1. (0, -15): Substitute x = 0 into the equation: y = 5(0) - 15 = -15. The calculated y value matches the table, so this point is correct.
  2. (3, 0): Substitute x = 3 into the equation: y = 5(3) - 15 = 15 - 15 = 0. The calculated y value matches the table, so this point is also correct.
  3. (5, 10): Substitute x = 5 into the equation: y = 5(5) - 15 = 25 - 15 = 10. The calculated y value matches the table, confirming this point's accuracy.
  4. (8, 15): Substitute x = 8 into the equation: y = 5(8) - 15 = 40 - 15 = 25. Here, the calculated y value (25) does not match the y value in the table (15). This indicates an error in the calculation for this point.

Pinpointing the Incorrect Calculation: The Case of (8, 15)

Through our step-by-step verification, we've identified that the point (8, 15) is the one Elliott calculated incorrectly. When x = 8 is substituted into the equation y = 5x - 15, the correct y value should be 25, not 15.

This discrepancy highlights the importance of careful substitution and arithmetic when working with linear equations and coordinate pairs. A small error in calculation can lead to an incorrect point and a misrepresentation of the line.

Common Pitfalls in Coordinate Pair Calculations

Several common errors can occur when calculating coordinate pairs for linear equations. Being aware of these pitfalls can help prevent mistakes and ensure accurate results. Some common mistakes include:

  • Incorrect substitution: Substituting the x value into the equation incorrectly, such as swapping the x and y values or misplacing the value within the equation.
  • Arithmetic errors: Making mistakes in the arithmetic operations, such as multiplication or subtraction, can lead to an incorrect y value.
  • Sign errors: Neglecting negative signs or applying them incorrectly can significantly alter the result.
  • Order of operations: Failing to follow the correct order of operations (PEMDAS/BODMAS) can lead to errors in the calculation.

To avoid these pitfalls, it's crucial to double-check each step of the calculation, pay close attention to signs and order of operations, and use a calculator if needed to minimize arithmetic errors.

The Significance of Accurate Coordinate Pairs

Accurate coordinate pairs are fundamental in understanding and representing linear equations graphically. Each correct coordinate pair represents a point that lies on the line defined by the equation. Plotting these points on a coordinate plane allows us to visualize the line and its properties, such as its slope and intercepts.

Incorrect coordinate pairs, on the other hand, can lead to a distorted representation of the line. If one or more points are plotted incorrectly, the resulting line will not accurately reflect the equation, and any conclusions drawn from the graph may be flawed.

Therefore, ensuring the accuracy of coordinate pairs is paramount in various mathematical and scientific applications where linear equations and graphs are used, such as data analysis, modeling, and predictions.

Mastering Linear Equations: Practice and Application

The ability to work with linear equations and coordinate pairs is a cornerstone of mathematical proficiency. To solidify your understanding and skills in this area, consistent practice and application are essential. Here are some ways to enhance your mastery of linear equations:

  • Solve a variety of problems: Work through a range of problems involving different linear equations and scenarios. This will expose you to various techniques and challenges, strengthening your problem-solving abilities.
  • Graph linear equations: Practice plotting linear equations on a coordinate plane using coordinate pairs. This will help you visualize the relationship between the equation and its graphical representation.
  • Identify slope and intercepts: Learn how to determine the slope and intercepts of a linear equation from its equation or graph. These properties provide valuable information about the line's characteristics.
  • Real-world applications: Explore real-world applications of linear equations, such as modeling relationships between quantities, predicting trends, and solving optimization problems. This will demonstrate the practical relevance of linear equations in various fields.

By engaging in these activities, you can develop a deep understanding of linear equations and their applications, paving the way for success in more advanced mathematical concepts.

Conclusion: Precision in Calculations

In conclusion, this problem underscores the importance of precision in mathematical calculations, particularly when dealing with linear equations and coordinate pairs. By carefully substituting values and verifying results, we can identify and correct errors, ensuring an accurate representation of the equation.

The exercise of identifying Elliott's miscalculation not only reinforces our understanding of linear equations but also highlights the significance of attention to detail in mathematical problem-solving. Mastery of these fundamental concepts is crucial for success in higher-level mathematics and its applications in various fields.

By understanding the principles of linear equations, practicing calculations diligently, and remaining vigilant for potential errors, we can confidently navigate the world of mathematics and its real-world applications. The journey of mathematical discovery is paved with precision and accuracy, leading to a deeper appreciation of the beauty and power of this fundamental discipline.