Solve For C: C^2 - 8c + 24 = 12

by Andrew McMorgan 32 views

Hey math whizzes and number crunchers! Today, we're diving into a classic algebra problem that's all about isolating a variable. We've got the equation c2βˆ’8c+24=12c^2 - 8c + 24 = 12, and our mission, should we choose to accept it, is to find the value(s) of cc that make this equation true. This isn't just about getting an answer; it's about understanding the process, honing those algebraic skills, and maybe even having a little fun with numbers. So, grab your calculators, sharpen your pencils, and let's break this down step by step. We'll explore different methods, discuss why certain approaches work, and make sure you feel confident tackling similar problems in the future. Ready to get your math on?

Getting the Equation Ready for Action

The first crucial step when you're trying to solve for c in any equation, especially one involving a quadratic term like c2c^2, is to get it into a standard form. For quadratic equations, the standard form is typically ax2+bx+c=0ax^2 + bx + c = 0. Our current equation is c2βˆ’8c+24=12c^2 - 8c + 24 = 12. See how the '12' is hanging out on the right side? We need to move that over to the left to make the right side equal to zero. This is a fundamental algebraic maneuver. To do this, we simply subtract 12 from both sides of the equation. Remember, whatever you do to one side, you must do to the other to maintain the balance of the equation. So, we have: c2βˆ’8c+24βˆ’12=12βˆ’12c^2 - 8c + 24 - 12 = 12 - 12. This simplifies to c2βˆ’8c+12=0c^2 - 8c + 12 = 0. Now, this beauty is in our standard quadratic form, where a=1a=1, b=βˆ’8b=-8, and the constant term is 1212. This simplified form is way easier to work with, whether we plan to factor, use the quadratic formula, or complete the square. It's like preparing your ingredients before you start cooking; you need everything in place for the best results. So, give yourself a pat on the back – you've just taken a significant step towards solving for cc!

Factoring: The Elegant Solution (If Possible)

With our equation now in the tidy form c2βˆ’8c+12=0c^2 - 8c + 12 = 0, our next thought is often: can we factor this bad boy? Factoring a quadratic expression means breaking it down into the product of two linear expressions. For an equation of the form c2+bc+d=0c^2 + bc + d = 0, we're looking for two numbers that multiply to give us dd (in our case, 12) and add up to give us bb (in our case, -8). This is where a bit of number sense comes in handy, guys. Let's list pairs of numbers that multiply to 12: (1, 12), (2, 6), (3, 4). We also need to consider negative pairs since our target sum is negative: (-1, -12), (-2, -6), (-3, -4). Now, let's check the sums of these pairs: 1+12=131+12=13, 2+6=82+6=8, 3+4=73+4=7, βˆ’1+(βˆ’12)=βˆ’13-1+(-12)=-13, βˆ’2+(βˆ’6)=βˆ’8-2+(-6)=-8, βˆ’3+(βˆ’4)=βˆ’7-3+(-4)=-7. Bingo! The pair -2 and -6 multiplies to 12 and adds up to -8. This means we can factor our quadratic expression as (cβˆ’2)(cβˆ’6)=0(c - 2)(c - 6) = 0. This is super cool because now we have two factors whose product is zero. The only way for a product of two numbers to be zero is if at least one of the numbers is zero. This principle, known as the Zero Product Property, is our golden ticket to finding the values of cc. So, we set each factor equal to zero: cβˆ’2=0c - 2 = 0 or cβˆ’6=0c - 6 = 0. Solving these simple linear equations gives us our solutions: c=2c = 2 and c=6c = 6. It’s so satisfying when factoring works out neatly, right?

The Quadratic Formula: Your Reliable Backup Plan

Sometimes, factoring isn't as straightforward, or perhaps the numbers just don't cooperate. That's where the quadratic formula comes to the rescue! This is a universal tool that works for any quadratic equation in the form ax2+bx+c=0ax^2 + bx + c = 0. The formula itself is:

c=βˆ’bΒ±b2βˆ’4ac2ac = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Even if factoring seemed like a dead end, the quadratic formula will always give you the answers. In our equation, c2βˆ’8c+12=0c^2 - 8c + 12 = 0, we identified a=1a=1, b=βˆ’8b=-8, and c=12c=12 (note: this 'c' in the formula is different from the variable we're solving for; it's the constant term in the standard quadratic equation). Now, we just plug these values into the formula. Let's do it carefully:

c=βˆ’(βˆ’8)Β±(βˆ’8)2βˆ’4(1)(12)2(1)c = \frac{-(-8) \pm \sqrt{(-8)^2 - 4(1)(12)}}{2(1)}

First, simplify the terms inside the formula: βˆ’(βˆ’8)-(-8) becomes 88. (βˆ’8)2(-8)^2 is 6464. And 4(1)(12)4(1)(12) is 4848. So, the formula looks like this:

c=8Β±64βˆ’482c = \frac{8 \pm \sqrt{64 - 48}}{2}

Now, calculate the value under the square root (this part is called the discriminant): 64βˆ’48=1664 - 48 = 16. So, we have:

c=8Β±162c = \frac{8 \pm \sqrt{16}}{2}

The square root of 16 is 4. So, we get:

c=8Β±42c = \frac{8 \pm 4}{2}

This 'Β±\pm' symbol means we have two possible solutions. One where we add 4, and one where we subtract 4.

  • Solution 1 (using +): c=8+42=122=6c = \frac{8 + 4}{2} = \frac{12}{2} = 6
  • Solution 2 (using -): c=8βˆ’42=42=2c = \frac{8 - 4}{2} = \frac{4}{2} = 2

See? We get the exact same solutions, c=6c=6 and c=2c=2, that we found through factoring. The quadratic formula is an absolute lifesaver, especially when dealing with equations that have messy numbers or no simple integer solutions. It's your trusty sidekick in the world of algebra, guaranteeing you can find the roots of any quadratic equation.

Completing the Square: A Deeper Understanding

Another powerful technique for solving quadratic equations, and one that's fundamental to understanding the derivation of the quadratic formula, is completing the square. This method is particularly useful when you need to rewrite a quadratic expression in the form (xβˆ’h)2=k(x-h)^2 = k. Let's revisit our standardized equation: c2βˆ’8c+12=0c^2 - 8c + 12 = 0. To complete the square, we want to manipulate the left side (c2βˆ’8cc^2 - 8c) so that it becomes a perfect square trinomial. A perfect square trinomial looks like (cβˆ’h)2=c2βˆ’2hc+h2(c - h)^2 = c^2 - 2hc + h^2. Comparing c2βˆ’8cc^2 - 8c to c2βˆ’2hcc^2 - 2hc, we can see that βˆ’8c-8c must equal βˆ’2hc-2hc. If we divide both sides by βˆ’2c-2c, we find h=4h=4. So, we need an h2h^2 term, which is 42=164^2 = 16.

To make this happen, we first isolate the terms with cc on one side and the constant on the other. So, from c2βˆ’8c+12=0c^2 - 8c + 12 = 0, we move the constant term: c2βˆ’8c=βˆ’12c^2 - 8c = -12. Now, we need to add our calculated value (h2=16h^2=16) to both sides of the equation to maintain balance and create that perfect square trinomial on the left.

c2βˆ’8c+16=βˆ’12+16c^2 - 8c + 16 = -12 + 16

The left side, c2βˆ’8c+16c^2 - 8c + 16, is now a perfect square, which can be written as (cβˆ’4)2(c - 4)^2. The right side simplifies to 44. So, our equation becomes:

(cβˆ’4)2=4(c - 4)^2 = 4

Now that we have a squared term isolated, we can take the square root of both sides. Remember to include both the positive and negative roots on the right side:

(cβˆ’4)2=Β±4\sqrt{(c - 4)^2} = \pm \sqrt{4}

cβˆ’4=Β±2c - 4 = \pm 2

Finally, we solve for cc by adding 4 to both sides:

c=4Β±2c = 4 \pm 2

This gives us our two solutions:

  • Solution 1: c=4+2=6c = 4 + 2 = 6
  • Solution 2: c=4βˆ’2=2c = 4 - 2 = 2

Just like with factoring and the quadratic formula, completing the square yields the same answers: c=2c=2 and c=6c=6. While it might seem like more work sometimes, understanding completing the square is incredibly valuable. It helps you grasp the structure of quadratic equations and is the foundation for many other mathematical concepts. It’s a technique that really builds a deeper appreciation for algebraic manipulation, guys.

Checking Your Work: The Final Seal of Approval

So, we've found our potential solutions for cc: 22 and 66. But are they correct? The best way to be absolutely sure is to check your work by plugging each value back into the original equation: c2βˆ’8c+24=12c^2 - 8c + 24 = 12. This step is super important and often overlooked, but it's your final seal of approval.

Let's check c=2c=2:

Substitute c=2c=2 into the original equation:

(2)2βˆ’8(2)+24=12(2)^2 - 8(2) + 24 = 12

4βˆ’16+24=124 - 16 + 24 = 12

βˆ’12+24=12-12 + 24 = 12

12=1212 = 12

Awesome! Since the left side equals the right side, c=2c=2 is a valid solution.

Now, let's check c=6c=6:

Substitute c=6c=6 into the original equation:

(6)2βˆ’8(6)+24=12(6)^2 - 8(6) + 24 = 12

36βˆ’48+24=1236 - 48 + 24 = 12

βˆ’12+24=12-12 + 24 = 12

12=1212 = 12

Fantastic! c=6c=6 also makes the original equation true. Both our solutions are confirmed. This checking process is your safety net, ensuring you haven't made any calculation errors along the way. It's a small step that guarantees accuracy and builds confidence in your problem-solving abilities. Always take the time to check your answers, especially in exams!

Conclusion: Mastering the Quadratic Equation

We've successfully tackled the equation c2βˆ’8c+24=12c^2 - 8c + 24 = 12 using three powerful methods: factoring, the quadratic formula, and completing the square. Each method, while different in approach, led us to the same correct solutions: c=2c = 2 and c=6c = 6. You guys have learned how to rearrange equations into standard form, apply the Zero Product Property through factoring, utilize the universal quadratic formula, and perform the insightful technique of completing the square. Furthermore, we emphasized the critical step of checking our solutions by substituting them back into the original equation. Mastering these techniques not only solves this specific problem but equips you with essential skills for countless other mathematical challenges. Remember, practice makes perfect! The more you work through these types of problems, the more intuitive and faster you'll become. Keep exploring, keep questioning, and keep solving! Happy calculating!