Unlock $x$: Solving $9 - 4x = 57$

by Andrew McMorgan 34 views

Hey math whizzes and number crunchers! Today, we're diving deep into the awesome world of algebra to solve a classic equation: 9βˆ’4x=579 - 4x = 57. Don't let it intimidate you, guys. We're going to break it down step-by-step, making it super clear how to find that elusive value of xx. This isn't just about getting the right answer; it's about understanding the process, the logic behind it, and how it applies to so many other problems you'll encounter. Think of it like unlocking a puzzle, where each step brings you closer to the final solution. We'll be using fundamental algebraic principles, which are the building blocks for more complex mathematical concepts. So, grab your calculators (or just your sharp minds!), and let's get started on unraveling this equation. By the end of this, you'll not only know how to solve 9βˆ’4x=579 - 4x = 57 but also feel more confident tackling similar algebraic challenges. We're aiming to demystify algebra and show you just how accessible and even fun it can be when you approach it the right way. Ready to unlock the value of xx and boost your math game? Let's do this!

The Goal: Isolating xx

Alright team, our main mission when we're faced with an equation like 9βˆ’4x=579 - 4x = 57 is to isolate xx. What does that mean? It means we want to get xx all by itself on one side of the equals sign. Think of the equals sign as a balanced scale. Whatever you do to one side, you must do to the other side to keep it balanced. Our goal is to move all the numbers that aren't xx to the other side, leaving xx as the star of the show. This is the fundamental principle of solving linear equations. We use inverse operations to undo the operations that are currently being applied to xx. For instance, if a number is being added to xx, we subtract it from both sides. If a number is being multiplied by xx, we divide both sides by that number. It's all about strategic manipulation to simplify the equation until xx is staring back at us. So, when we look at 9βˆ’4x=579 - 4x = 57, we see xx is being multiplied by -4, and then 9 is being added to that result. To isolate xx, we'll need to perform the inverse operations in the reverse order. This means we'll deal with the addition/subtraction first, and then the multiplication/division. This systematic approach ensures accuracy and builds a solid foundation for more advanced algebra. Mastering this concept is crucial, as it underpins much of higher mathematics and its applications in science, engineering, economics, and beyond. So, let's keep our focus sharp as we start peeling back the layers of this equation, aiming for that sweet victory of isolating xx.

Step 1: Dealing with the Constant Term

The first step in our quest to isolate xx in the equation 9βˆ’4x=579 - 4x = 57 is to tackle the constant term that's on the same side as our xx variable. Right now, that constant term is 9. Notice that it's being added to the βˆ’4x-4x term (even though it's written first, it's like +9βˆ’4x+9 - 4x). To get rid of this +9+9, we need to perform its inverse operation, which is subtraction. So, we're going to subtract 9 from both sides of the equation. This is where the balanced scale analogy comes in handy. If we subtract 9 from the left side, we must also subtract 9 from the right side to maintain equality. Let's see what happens:

9βˆ’4xβˆ’9=57βˆ’99 - 4x - 9 = 57 - 9

On the left side, the +9+9 and βˆ’9-9 cancel each other out, leaving us with just βˆ’4x-4x. On the right side, we perform the subtraction: 57βˆ’9=4857 - 9 = 48. So, our equation now simplifies to:

βˆ’4x=48-4x = 48

See? We're one step closer! By strategically removing the constant term, we've simplified the equation and brought the xx term closer to being alone. This initial move is crucial because it isolates the term containing xx, allowing us to focus on the coefficient multiplying xx in the next stage. It's a common strategy in solving linear equations: address additive/subtractive components first before moving on to multiplicative/divisive ones. This keeps the process clean and manageable. Remember, every operation is about maintaining balance and systematically reducing the complexity of the equation until our target variable is isolated. Keep this principle in mind, and you'll be solving equations like a pro!

Step 2: Undoing the Multiplication

We've successfully simplified our equation to βˆ’4x=48-4x = 48. Now, we can see that xx is being multiplied by βˆ’4-4. To get xx all by itself, we need to perform the inverse operation of multiplication, which is division. We need to divide both sides of the equation by -4. Remember, we're dividing by the entire coefficient, including its sign. This is super important because it ensures we get the correct value for xx.

Let's do it:

βˆ’4xβˆ’4=48βˆ’4\frac{-4x}{-4} = \frac{48}{-4}

On the left side, the βˆ’4-4 in the numerator and the βˆ’4-4 in the denominator cancel each other out, leaving us with just xx. On the right side, we perform the division: 4848 divided by βˆ’4-4. Since a positive number divided by a negative number results in a negative number, we have:

x=βˆ’12x = -12

And there you have it, guys! We've successfully isolated xx and found its value. The solution to the equation 9βˆ’4x=579 - 4x = 57 is x=βˆ’12x = -12. This step, dividing by the coefficient, is the final move to isolate the variable. It's essential to divide by the exact coefficient, including its sign, to correctly determine the value of xx. If we had divided by 4 instead of -4, we would have ended up with x=βˆ’12x = -12, which is correct, but dividing by -4 directly handles the sign in one go. It's a neat trick to keep your calculations straightforward. We've gone from a complex-looking equation to a simple, elegant solution by applying basic algebraic rules. High five!

Verification: Is x=βˆ’12x = -12 Correct?

Now, a crucial part of solving any equation is to verify our answer. Does x=βˆ’12x = -12 really satisfy the original equation 9βˆ’4x=579 - 4x = 57? There's only one way to find out: plug our found value of xx back into the original equation and see if both sides are equal. This verification step is like a final check, ensuring all our hard work paid off and that we haven't made any slip-ups along the way. It builds confidence in our solutions and reinforces the understanding that equations represent a true balance.

Let's substitute x=βˆ’12x = -12 into the equation 9βˆ’4x=579 - 4x = 57:

9βˆ’4(βˆ’12)=579 - 4(-12) = 57

First, we handle the multiplication: βˆ’4-4 times βˆ’12-12. Remember, a negative number multiplied by a negative number results in a positive number. So, βˆ’4imesβˆ’12=48-4 imes -12 = 48.

Now, substitute that back into the equation:

9+48=579 + 48 = 57

Finally, perform the addition on the left side: 9+48=579 + 48 = 57.

57=5757 = 57

Boom! Both sides of the equation are equal. This confirms that our solution, x=βˆ’12x = -12, is absolutely correct. This verification process is a powerful tool in your mathematical arsenal. It's not just about checking the answer; it's about reinforcing the rules of algebra and understanding how solutions maintain the integrity of the equation. So, always take that extra moment to verify your answers – it's a small step that yields huge dividends in accuracy and understanding. You've officially conquered this equation, guys!

Conclusion: Mastering Algebraic Equations

So there you have it, math enthusiasts! We've successfully navigated the steps to solve the equation 9βˆ’4x=579 - 4x = 57, arriving at the definitive answer x=βˆ’12x = -12. We started by understanding our goal: to isolate xx using inverse operations while maintaining the balance of the equation. We then meticulously subtracted 9 from both sides to handle the constant term, simplifying the equation to βˆ’4x=48-4x = 48. The final push involved dividing both sides by βˆ’4-4 to undo the multiplication and reveal the value of xx. And, of course, we finished with a crucial verification step, plugging our answer back into the original equation to confirm its accuracy. This entire process highlights the systematic and logical nature of algebra. Each step is a deliberate move, building upon the last to achieve the desired outcome. This isn't just about one equation; it's about building a toolkit of skills that will serve you well in countless future mathematical endeavors, from geometry to calculus and beyond. Remember, guys, the key takeaways are: always aim to isolate the variable, perform the same operation on both sides, and don't forget to verify your solution. Practice makes perfect, so don't hesitate to tackle more equations like this. The more you practice, the more intuitive these steps will become, and the more confident you'll feel in your mathematical abilities. Keep exploring, keep solving, and keep pushing your boundaries in the fascinating world of mathematics! You've got this!