Best First Step: Solving $2\sqrt{x-6}=8$ Equation

by Omar Yusuf 50 views

Hey everyone! Let's dive into solving equations, specifically focusing on how to pick the best first step. This is super important because the right first move can make a tricky problem way easier. We're going to break down an example equation and talk through the thought process, so you'll be a pro at this in no time. Let's jump in!

Understanding the Equation: 2xβˆ’6=82\sqrt{x-6}=8

So, our equation is 2xβˆ’6=82\sqrt{x-6}=8. When we look at this, the first thing we need to do is identify what's going on. We see a square root, which means we have a radical equation. Radical equations have a variable tucked away inside a radical, in this case, a square root. Our goal is always to isolate the variable, which means getting 'x' all by itself on one side of the equation. But, we can't just jump in and start subtracting or adding things willy-nilly. We need a strategy!

The key to solving radical equations is to get rid of that radical first. Think of it like unwrapping a present – you need to remove the outer layers before you can get to the good stuff inside. But before we can eliminate the square root, it's super helpful to isolate it as much as possible. This means we want to get the xβˆ’6\sqrt{x-6} part by itself on one side of the equation. There's a '2' hanging out in front of the square root, and it's multiplying the radical expression. This is a crucial observation because it tells us our first step. Remember, we are focusing on choosing the best first step, not just any step.

Now, why is isolating the radical so important? Well, it simplifies the process of getting rid of the square root. When the radical is isolated, we can square both sides of the equation, and the square root will disappear. If we try to square both sides before isolating the radical, things get messy real fast. We'd have to deal with squaring a binomial (something plus something else), and that introduces extra terms and complications. So, isolating the radical is like taking a shortcut through the problem – it saves us time and effort in the long run. It’s all about working smart, not hard, right? This first step dramatically impacts how smoothly the rest of the solution unfolds, making it a pivotal decision point in solving equations. By prioritizing the isolation of the radical term, you set the stage for a cleaner and more efficient algebraic manipulation process.

The Best First Step: Divide Both Sides by 2

Okay, so we know we want to isolate the square root. Looking at our equation, 2xβˆ’6=82\sqrt{x-6}=8, what's the easiest way to get the xβˆ’6\sqrt{x-6} by itself? We've got that '2' multiplying it, right? The best first step here is to divide both sides of the equation by 2. Remember, whatever we do to one side of the equation, we have to do to the other side to keep things balanced – it's like the golden rule of algebra!

When we divide both sides by 2, we get: (2xβˆ’6)/2=8/2(2\sqrt{x-6})/2 = 8/2. On the left side, the '2's cancel out, leaving us with xβˆ’6\sqrt{x-6}. On the right side, 8 divided by 2 is 4. So, our equation now looks like this: xβˆ’6=4\sqrt{x-6} = 4. See how much simpler that is already? We've successfully isolated the square root, and now we're in a great position to get rid of it.

Why is this the best first step, though? Couldn't we do something else? Well, think about it. We could try squaring both sides right away, but that would mean squaring the entire left side, including the '2'. That would lead to (2xβˆ’6)2=22βˆ—(xβˆ’6)2=4(xβˆ’6)(2\sqrt{x-6})^2 = 2^2 * (\sqrt{x-6})^2 = 4(x-6). See how we've introduced a '4' that we now have to deal with? It's not wrong, but it makes the problem a bit more complicated than it needs to be. Dividing by 2 first simplifies the equation right off the bat, making the subsequent steps much easier. Plus, isolating the radical minimizes potential errors and streamlines the algebraic process. This strategic move ensures that the equation is in the most manageable form before more complex operations are applied.

Why Not Square Both Sides Immediately?

Now, you might be wondering, why not just square both sides right away? It seems like it would get rid of the square root, right? Well, you could do that, but it’s like taking the scenic route when there’s a highway available. It's not the most efficient way, and it can lead to more work and a higher chance of making mistakes. Let's see why.

If we were to square both sides of the original equation, 2xβˆ’6=82\sqrt{x-6}=8, immediately, we'd have to square the entire left side, including the '2'. This means we'd have (2xβˆ’6)2=82(2\sqrt{x-6})^2 = 8^2. When we square the left side, we're actually squaring both the '2' and the xβˆ’6\sqrt{x-6}. So, it becomes 22βˆ—(xβˆ’6)2=4(xβˆ’6)2^2 * (\sqrt{x-6})^2 = 4(x-6). On the right side, 828^2 is 64. So, our equation becomes 4(xβˆ’6)=644(x-6) = 64.

Now, we're not stuck, but we've introduced an extra step. We have to distribute the '4' on the left side, which gives us 4xβˆ’24=644x - 24 = 64. Then, we'd add 24 to both sides, getting 4x=884x = 88, and finally, divide by 4 to get x=22x = 22. It works, but look at all those extra steps! We had to distribute, add, and then divide. Compare that to what happens when we divide by 2 first.

When we divided by 2 first, we got xβˆ’6=4\sqrt{x-6} = 4. Then, we squared both sides: (xβˆ’6)2=42(\sqrt{x-6})^2 = 4^2, which simplifies to xβˆ’6=16x-6 = 16. Just one more step: add 6 to both sides, and we get x=22x = 22. See how much cleaner that was? It's fewer steps, fewer chances to make a mistake, and overall, a more efficient way to solve the equation. This illustrates the importance of strategic thinking in algebra; choosing the optimal sequence of operations can significantly impact the complexity and time required to find a solution. Understanding these nuances empowers you to approach problems with greater confidence and effectiveness.

Solving the Simplified Equation: xβˆ’6=4\sqrt{x-6} = 4

Okay, great! We've chosen the best first step and simplified our equation to xβˆ’6=4\sqrt{x-6} = 4. Now, let's actually solve for 'x'. We've got the square root isolated, which is exactly what we wanted. So, how do we get rid of a square root? We do the inverse operation: we square it! Just like before, whatever we do to one side, we have to do to the other. So, we'll square both sides of the equation.

Squaring both sides gives us (xβˆ’6)2=42(\sqrt{x-6})^2 = 4^2. The square root and the square cancel each other out on the left side, leaving us with xβˆ’6x-6. On the right side, 424^2 is 16. So, our equation now looks like this: xβˆ’6=16x-6 = 16. We're almost there!

Now, we just need to get 'x' by itself. We have 'x' minus 6, so the opposite of subtracting 6 is adding 6. We'll add 6 to both sides of the equation: xβˆ’6+6=16+6x-6 + 6 = 16 + 6. This simplifies to x=22x = 22. Hooray, we found our solution!

But wait, we're not quite done yet. With radical equations, there's one more crucial step: we need to check our solution. Why? Because squaring both sides of an equation can sometimes introduce extraneous solutions – solutions that seem to work algebraically but don't actually satisfy the original equation. It’s like a mirage in the desert; it looks like water, but it’s not really there. Therefore, validating the solution is a critical safeguard in the equation-solving process.

Checking the Solution

So, we found that x=22x = 22. To check if this is a valid solution, we need to plug it back into the original equation, 2xβˆ’6=82\sqrt{x-6}=8, and see if it makes the equation true. Let's do it!

We substitute 22 for 'x': 222βˆ’6=82\sqrt{22-6} = 8. First, we simplify inside the square root: 22βˆ’6=1622 - 6 = 16. So, we have 216=82\sqrt{16} = 8. Next, we evaluate the square root: the square root of 16 is 4, so we have 2βˆ—4=82 * 4 = 8. Finally, we multiply: 2βˆ—4=82 * 4 = 8. So, we have 8=88 = 8. This is a true statement! That means x=22x = 22 is indeed a valid solution.

If we had plugged in our solution and gotten something like 8=98 = 9, that would mean our solution was extraneous, and we'd have to discard it. But in this case, our solution checks out, so we're golden! Checking the answer is like the final polish on your work, ensuring accuracy and completeness. The habit of verifying solutions, especially in radical equations, prevents the acceptance of extraneous results and reinforces the validity of the algebraic manipulations performed.

Conclusion: Strategic Steps in Equation Solving

Alright, guys, we've covered a lot! We started with the equation 2xβˆ’6=82\sqrt{x-6}=8, and we talked about the importance of choosing the best first step. We saw that dividing both sides by 2 to isolate the square root was the smartest move because it simplified the problem and made the subsequent steps much easier. We also talked about why squaring both sides immediately, while not technically wrong, is less efficient and can lead to more work.

Then, we solved the simplified equation, remembering to square both sides to get rid of the square root and then isolating 'x'. Finally, we emphasized the critical step of checking our solution to make sure it's valid and not extraneous. The key takeaway here is that strategic thinking is just as important as the algebraic manipulations themselves. Choosing the right first step can make all the difference in how smoothly you solve an equation. It's like building a house – you need a solid foundation before you can start putting up the walls. So, next time you're faced with a radical equation (or any equation, for that matter), take a moment to think about the best way to approach it. What can you do to simplify things right off the bat? Isolating radicals, combining like terms, and looking for opportunities to reduce complexity are all great strategies.

By mastering these techniques, you'll not only become more proficient at solving equations but also develop a deeper understanding of algebraic principles. Keep practicing, and you'll be an equation-solving master in no time! Remember, the journey of solving equations is not just about finding the answer; it’s also about developing critical thinking and problem-solving skills that will benefit you in all areas of life. So, embrace the challenge, and enjoy the process of unraveling mathematical mysteries!