Solving $x^2 = 27$: A Step-by-Step Guide

by Andrew McMorgan 41 views

Hey guys! Today, we're diving into a fun little math problem that involves solving a quadratic equation. Specifically, we're tackling the equation x2=27x^2 = 27. If you're scratching your head wondering how to approach this, don't worry! We're going to break it down step by step, so you'll not only understand the solution but also the reasoning behind it. This is super important for building a solid foundation in algebra, which will help you crush more complex problems later on. So, grab your favorite beverage, get comfy, and let's get started!

Understanding the Problem

Before we jump into the nitty-gritty, let's make sure we understand what the problem is asking. We need to find all the real numbers, represented by the variable x, that when squared (multiplied by itself) result in 27. This means we're looking for the values of x that satisfy the equation x2=27x^2 = 27. Remember, a real number is any number that can be found on a number line โ€“ this includes positive numbers, negative numbers, fractions, decimals, and even irrational numbers like square roots. So, we're not dealing with imaginary numbers here, just good old real values. This understanding is crucial because it sets the stage for the methods we'll use to solve the equation. Recognizing the type of numbers we're looking for helps us narrow down our approach and avoid potential pitfalls. Okay, now that we're clear on what we're trying to achieve, let's move on to the solution!

Step-by-Step Solution

Alright, let's get our hands dirty and solve this equation! The key to solving x2=27x^2 = 27 is to isolate x. To do this, we need to undo the squaring operation. And how do we do that? By taking the square root of both sides of the equation! This is a fundamental concept in algebra: whatever operation you perform on one side of the equation, you must perform on the other side to maintain the balance. So, let's apply the square root to both sides:

x2=27\sqrt{x^2} = \sqrt{27}

Now, here's a critical point: When we take the square root of a variable squared, we need to consider both the positive and negative roots. Why? Because both a positive number and its negative counterpart, when squared, will result in a positive number. For example, both 3 squared and -3 squared equal 9. So, the square root of x2x^2 is actually โˆฃxโˆฃ|x|, which means x can be either the positive or negative square root of 27. This is a common place where students might miss a solution, so it's super important to remember! Therefore, we have:

x=ยฑ27x = \pm\sqrt{27}

The ยฑ\pm symbol means "plus or minus," indicating that there are two possible solutions: the positive square root of 27 and the negative square root of 27.

Simplifying the Square Root

We're not quite done yet! While we've found the solutions in their raw form, we can simplify 27\sqrt{27}. Simplifying radicals is all about finding perfect square factors within the radicand (the number under the square root symbol). In this case, 27 can be factored into 9 and 3, where 9 is a perfect square (since 32=93^2 = 9). So, we can rewrite 27\sqrt{27} as:

27=9โ‹…3\sqrt{27} = \sqrt{9 \cdot 3}

Now, we can use the property of square roots that says aโ‹…b=aโ‹…b\sqrt{a \cdot b} = \sqrt{a} \cdot \sqrt{b}. Applying this property, we get:

9โ‹…3=9โ‹…3\sqrt{9 \cdot 3} = \sqrt{9} \cdot \sqrt{3}

We know that 9=3\sqrt{9} = 3, so we can substitute that in:

9โ‹…3=33\sqrt{9} \cdot \sqrt{3} = 3\sqrt{3}

Therefore, 27\sqrt{27} simplifies to 333\sqrt{3}. This simplification is essential because it presents the solution in its most concise and elegant form. It also makes it easier to compare and manipulate the solution in further calculations if needed. Simplification is a fundamental skill in mathematics, so make sure you're comfortable with it!

Final Solutions

Now that we've simplified the square root, we can write our final solutions for x. Remember, we had two possible solutions: the positive and negative square roots of 27. So, we substitute our simplified form back in:

x=ยฑ33x = \pm 3\sqrt{3}

This means we have two distinct solutions:

  • x=33x = 3\sqrt{3}
  • x=โˆ’33x = -3\sqrt{3}

These are the two real numbers that, when squared, equal 27. We've successfully solved the equation! It's always a good idea to double-check your solutions by plugging them back into the original equation to make sure they work. In this case, squaring both 333\sqrt{3} and โˆ’33-3\sqrt{3} will indeed result in 27. So, we can be confident in our answer. Woohoo!

Key Takeaways

Let's recap the key steps we took to solve this equation:

  1. Take the square root of both sides: This is the fundamental operation to isolate x.
  2. Remember the ยฑ\pm: Don't forget to consider both positive and negative roots when taking the square root of a variable squared.
  3. Simplify radicals: Look for perfect square factors to simplify the square root.

These three steps are the cornerstone of solving equations of this type. By mastering them, you'll be well-equipped to tackle a wide range of quadratic equations. Remember, practice makes perfect! The more you work through problems like this, the more comfortable you'll become with the process. And that confidence is what will really help you shine in your math journey. Keep up the great work, guys!

Practice Problems

Want to test your newfound skills? Try solving these similar equations:

  1. x2=48x^2 = 48
  2. x2=75x^2 = 75
  3. x2=100x^2 = 100

Remember to follow the same steps we used in this example: take the square root of both sides, consider both positive and negative roots, and simplify the radicals. These practice problems will reinforce your understanding and help you build fluency in solving quadratic equations. Don't be afraid to make mistakes โ€“ that's how we learn! The key is to keep practicing and keep pushing yourself. You've got this!

Conclusion

So there you have it! We've successfully solved the equation x2=27x^2 = 27 and found the two real number solutions: x=33x = 3\sqrt{3} and x=โˆ’33x = -3\sqrt{3}. We also learned the important steps involved in solving equations of this type, including taking the square root of both sides, remembering the plus or minus, and simplifying radicals. Remember, math is like building with LEGOs โ€“ each concept builds on the previous one. By mastering these fundamental skills, you'll be able to tackle more complex problems with ease. Keep practicing, keep exploring, and most importantly, keep having fun with math! Until next time, keep those equations balanced, and I'll catch you in the next math adventure!