Solving Quadratic Equations: A Step-by-Step Guide

by Andrew McMorgan 50 views

Hey Plastik Magazine readers! Let's dive into a classic math problem: solving the quadratic equation (x−9)2−40=0(x-9)^2 - 40 = 0. Don't worry, this isn't as scary as it looks! We'll break it down step by step, making it super easy to understand. Get ready to flex those math muscles and learn something cool today. This particular problem is a great example of how we can use algebra to find the values of x that satisfy an equation. It's all about isolating x and figuring out its value. So, let's jump right in and unlock the secrets of this equation! We'll be using some basic algebraic manipulations, and trust me, you'll be surprised at how straightforward it is. By the end of this, you'll not only solve this specific equation but also gain a solid understanding of the general process for solving similar quadratic equations. Let's start with a clear, concise plan and then execute it, one step at a time, to make sure we arrive at the correct answer. The world of algebra might seem daunting at first, but with a little practice and a good grasp of the basics, you'll be solving equations like a pro in no time! Keep your eyes peeled and your mind open; it's going to be an exciting journey into the realm of mathematics! We are going to explore the steps involved, from the initial setup to the final answer. This will provide you with a comprehensive understanding of the entire process.

Step 1: Isolating the Squared Term

Alright, guys, our first step in solving the equation (x−9)2−40=0(x-9)^2 - 40 = 0 is to isolate the squared term, which is (x−9)2(x-9)^2. This means we want to get this term by itself on one side of the equation. To do this, we need to get rid of the -40. How do we do that? By adding 40 to both sides of the equation. This simple move keeps the equation balanced and brings us closer to our goal. When we add 40 to both sides, the equation transforms like magic! On the left side, the -40 and +40 cancel each other out, leaving us with just (x−9)2(x-9)^2. On the right side, we simply have 0 + 40, which equals 40. Now, we have a simplified equation where the squared term is isolated. This is a crucial step because it sets us up perfectly for the next step, where we'll deal with the square itself. Think of it like this: we're clearing the path so that we can easily find the value of x. The goal is always to get x alone, so everything else needs to be moved away. In algebra, every move we make has a purpose, and isolating the squared term is the key to unlocking our solution. Every move matters, so take your time and make sure you understand each step before moving on. By carefully isolating the term, you make the next steps much easier to handle. So, we're off to a great start, and the equation is already looking much friendlier, isn't it?

So, after adding 40 to both sides, we get the equation: (x−9)2=40(x-9)^2 = 40. We have successfully isolated the squared term, and we're ready for the next adventure!

Step 2: Taking the Square Root of Both Sides

Now that we've isolated the squared term, the next step is to get rid of the square. How do we do that? By taking the square root of both sides of the equation, of course! When we take the square root of (x−9)2(x-9)^2, we're left with (x−9)(x-9). But here's where it gets a little tricky, and important! Whenever you take the square root of a number, you need to consider both the positive and negative square roots. Remember, both a positive and a negative number, when squared, result in a positive number. So, the square root of 40 can be either positive or negative. We'll write this as ±40\pm\sqrt{40}. This plus-or-minus symbol is crucial because it accounts for both possible solutions to our equation. This step is about uncovering the two possible values of x that will satisfy the original equation. We're not just looking for one answer; we're hunting for two! It is important to remember this concept because it often trips up beginners. Don't worry; we are all here to learn and understand. It is better to get it right the first time and not have to redo the problem. We're now dealing with the square root of 40, which isn't a perfect square. But that's okay! We can simplify this a bit. Notice that 40 can be factored into 4×104 \times 10. And since the square root of 4 is 2, we can simplify 40\sqrt{40} to 2102\sqrt{10}. Now, our equation looks like this: x−9=±210x - 9 = \pm 2\sqrt{10}. This takes us closer to the final solution! We can now see the two possible values for x as they come into view. This is how we begin to solve for x, and it makes our next step that much easier!

So, after taking the square root of both sides, our equation becomes: x−9=±210x - 9 = \pm 2\sqrt{10}. Let's keep moving forward!

Step 3: Solving for x

Okay, team, we're in the home stretch now! Our equation is x−9=±210x - 9 = \pm 2\sqrt{10}. To solve for x, we simply need to get rid of the -9. How do we do that? By adding 9 to both sides of the equation. This will isolate x on one side and give us our solutions! When we add 9 to both sides, the -9 on the left side cancels out, leaving us with just x. On the right side, we have 9±2109 \pm 2\sqrt{10}. This means we have two possible solutions for x: one where we add 2102\sqrt{10} to 9, and another where we subtract 2102\sqrt{10} from 9. These are our two solutions! We've successfully isolated x, and we now know its two possible values. Remember, quadratic equations often have two solutions, and we've found them! This step is about tidying up and presenting our solutions in a clear, concise manner. We're bringing all the loose ends together and preparing to announce our answers. It's like putting the final touches on a masterpiece! Remember that solving for x means finding the value that makes the original equation true. Let's make sure we've done everything correctly! We are very close to reaching our final answers, so let us take a moment to be sure that we have everything in its place. These solutions tell us the points where the graph of the original equation crosses the x-axis. Therefore, it is important to know how to perform this step.

So, solving for x, we find that: x=9±210x = 9 \pm 2\sqrt{10}. We're done, guys!

Step 4: Writing the Final Solutions

Alright, folks, we're here at the finish line! Our final step is to write out the two solutions for x clearly. From our previous steps, we found that x=9±210x = 9 \pm 2\sqrt{10}. This means we have two solutions: one where we add 2102\sqrt{10} to 9, and another where we subtract 2102\sqrt{10} from 9. To write these out, we can say that: x1=9+210x_1 = 9 + 2\sqrt{10} and x2=9−210x_2 = 9 - 2\sqrt{10}. Here, we have clearly expressed our two solutions! These are the values of x that, when plugged back into the original equation (x−9)2−40=0(x-9)^2 - 40 = 0, will make the equation true. Isn't that cool? It's like finding a treasure and unlocking the secret! This step is about presenting our answers in a polished and professional way. We want to be sure that anyone reading our work can easily understand what our solutions are. It's also a good practice to double-check our work. While we've gone through the steps carefully, it's always smart to make sure everything is perfect! It's important to remember that these are the only two values of x that satisfy the original equation. No other value will work! Now, you can present your solutions with confidence and clarity! We have finished our work with the equations and are ready to move on. Let's make sure our solutions are in the right format and clearly stated!

Therefore, the solutions to the equation (x−9)2−40=0(x-9)^2 - 40 = 0 are: x1=9+210x_1 = 9 + 2\sqrt{10} and x2=9−210x_2 = 9 - 2\sqrt{10}. Congratulations!

Conclusion: You Did It!

And there you have it, Plastik Magazine readers! We've successfully solved the quadratic equation (x−9)2−40=0(x-9)^2 - 40 = 0. You've learned how to isolate the squared term, take the square root of both sides, solve for x, and write out your final solutions. This is a big win! Remember that the key is to break the problem down into smaller, manageable steps. Each step builds on the previous one, so take your time and make sure you understand each part of the process. Also, don't forget the plus-or-minus sign when taking the square root. That's a super important detail! Keep practicing, and you'll become a pro at solving quadratic equations in no time! Keep exploring the world of math and equations. You're doing a fantastic job, and your efforts are paying off! Always remember to have fun with math. It is just a big game that is made to be enjoyed. The more you do, the better you will get, so be patient with yourself. With a little determination, you can conquer any mathematical challenge that comes your way! Until next time, keep those equations in check, and keep solving! You've got this!