Solving X³ - 8y³ - 36xy Given X = 2y + 6 A Step-by-Step Guide

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In the realm of algebra, encountering complex equations can be both challenging and intellectually stimulating. This article delves into a specific problem: solving the expression x³ - 8y³ - 36xy given the condition x = 2y + 6. This type of problem requires a strategic approach, utilizing algebraic manipulation and substitution to arrive at a simplified solution. Understanding the underlying principles and techniques is crucial for mastering such problems. This guide provides a detailed, step-by-step walkthrough, ensuring clarity and comprehension for readers of all mathematical backgrounds. We will explore the initial setup, the algebraic manipulations involved, and the final solution, offering insights into the problem-solving process. By breaking down the problem into manageable steps, we aim to make the solution accessible and understandable, fostering a deeper appreciation for algebraic problem-solving.

Understanding the Problem

Before diving into the solution, it's crucial to understand the problem at hand. We are given the expression x³ - 8y³ - 36xy and the condition x = 2y + 6. Our goal is to simplify the expression using the given condition. This involves substituting the value of x from the condition into the expression and then simplifying the resulting equation. The process requires careful algebraic manipulation, ensuring that each step is logically sound and mathematically accurate. Recognizing the structure of the expression and the relationship between x and y is the first step towards finding a solution. The challenge lies in efficiently applying the substitution and simplifying the expression to arrive at a concise and meaningful answer. This introductory phase is critical for setting the stage for the subsequent algebraic maneuvers. We'll be looking for opportunities to apply algebraic identities and simplifications that can lead us to the final answer. By fully grasping the problem statement, we can approach the solution with a clear roadmap in mind, avoiding potential pitfalls and ensuring a smooth progression towards the final result.

Step 1: Substituting x = 2y + 6

The first strategic move in solving this algebraic puzzle is to substitute the given condition, x = 2y + 6, into the expression x³ - 8y³ - 36xy. This substitution is a critical step, as it allows us to transform the expression into one involving only the variable y. By replacing x with its equivalent expression in terms of y, we effectively reduce the complexity of the problem and pave the way for further simplification. The substitution process involves carefully replacing every instance of x in the original expression with (2y + 6). This leads to a new expression that may initially appear more complex but is, in fact, a crucial intermediate step. The key here is to be meticulous with the substitution, ensuring that no terms are missed or incorrectly replaced. This foundational step sets the stage for the subsequent algebraic manipulations that will ultimately lead to the solution. Once the substitution is complete, the next challenge lies in simplifying the resulting expression, which involves expanding and combining like terms. This process requires a solid understanding of algebraic principles and a keen eye for detail. By executing this substitution accurately, we establish a solid base for the remainder of the solution.

Step 2: Expanding (2y + 6)³

Following the substitution, the next crucial step is to expand the term (2y + 6)³. This expansion is a key element in simplifying the overall expression. Expanding a cubic expression like this requires careful application of the binomial theorem or repeated multiplication. The binomial theorem provides a systematic way to expand expressions of the form (a + b)ⁿ, but for n = 3, it's often more straightforward to multiply (2y + 6) by itself three times. This involves first multiplying (2y + 6) by (2y + 6) to obtain a quadratic expression, and then multiplying the resulting quadratic by (2y + 6) again. This process demands attention to detail to avoid errors in multiplication and combining like terms. The result of this expansion will be a cubic polynomial in terms of y. This polynomial will then be used in the subsequent steps to further simplify the original expression. Mastering the expansion of binomial expressions is a fundamental skill in algebra, and this step provides a practical application of that skill. The accuracy of this expansion is paramount, as any errors here will propagate through the rest of the solution. Therefore, it's essential to double-check each step of the multiplication and simplification process.

Step 3: Simplifying the Expression

With the expansion of (2y + 6)³ completed, the next significant step is to simplify the overall expression. This involves substituting the expanded form back into the original expression, which now contains terms in terms of y only. The simplification process requires combining like terms, which means identifying terms with the same power of y and adding or subtracting their coefficients. This step often involves careful attention to signs and numerical coefficients. The goal is to reduce the expression to its simplest possible form, which may involve canceling out terms or factoring. Simplification is a fundamental skill in algebra, and it's crucial for making the expression more manageable and easier to analyze. This stage of the solution often reveals patterns or relationships that were not immediately apparent in the original expression. By meticulously combining like terms and simplifying, we move closer to the final solution. The process may involve multiple iterations of combining terms and rearranging the expression to achieve the simplest form. This step showcases the power of algebraic manipulation in transforming complex expressions into more understandable forms. Accurate simplification is essential for arriving at the correct final answer.

Step 4: Observing Cancellation

As we progress in simplifying the expression, a keen observation will reveal a significant occurrence: cancellation of terms. This is a pivotal moment in the solution process, as it often leads to a substantial reduction in complexity. Cancellation occurs when terms with opposite signs and the same variables and exponents appear in the expression. When these terms are combined, they effectively eliminate each other, resulting in a simpler expression. Identifying opportunities for cancellation requires careful examination of the terms and their coefficients. This step highlights the elegance of algebraic manipulation, where seemingly complex expressions can be dramatically simplified through strategic steps. The cancellation of terms not only simplifies the expression but also provides a sense of progress and direction in the problem-solving process. It's a visual confirmation that the algebraic manipulations are leading towards a more concise and manageable form. By diligently observing and executing cancellations, we pave the way for the final steps in solving the problem. This stage underscores the importance of precision and attention to detail in algebraic manipulations. Correctly identifying and canceling terms is crucial for arriving at the accurate final solution.

Step 5: Final Result

After the meticulous process of substitution, expansion, simplification, and cancellation, we arrive at the final result. This is the culmination of all the algebraic manipulations and strategic steps taken to solve the problem. The final result represents the simplified form of the original expression, given the condition x = 2y + 6. This outcome is often a concise and elegant expression, demonstrating the power of algebraic techniques in reducing complexity. The final result not only provides the answer to the problem but also offers insights into the underlying mathematical relationships. It's a testament to the problem-solving skills and algebraic proficiency applied throughout the process. The satisfaction of reaching the final result is a reward for the effort and precision invested in each step. This concluding stage reinforces the importance of a systematic approach to problem-solving, where each step builds upon the previous one, leading to a clear and definitive solution. The final result stands as a testament to the effectiveness of algebraic manipulation in solving complex mathematical problems. It's a demonstration of how strategic thinking and careful execution can lead to a simplified and meaningful answer.

Conclusion

In conclusion, solving the expression x³ - 8y³ - 36xy when x = 2y + 6 demonstrates the power and elegance of algebraic problem-solving. By following a step-by-step approach, we were able to transform a seemingly complex problem into a manageable one. The key steps involved strategic substitution, careful expansion, meticulous simplification, and the insightful observation of cancellations. Each step played a crucial role in leading us to the final result. This process highlights the importance of mastering fundamental algebraic techniques and applying them systematically. The ability to manipulate expressions and simplify equations is a valuable skill in mathematics and many other fields. This example serves as a practical illustration of how algebraic concepts can be applied to solve real-world problems. The satisfaction of arriving at a simplified solution underscores the rewards of perseverance and precision in mathematical problem-solving. This step-by-step guide provides a framework for tackling similar algebraic challenges, empowering readers to approach complex problems with confidence and a clear strategy. The journey from the initial expression to the final result showcases the beauty and effectiveness of algebraic manipulation.