Unlocking Algebra: Simplifying Expressions Step-by-Step

by Andrew McMorgan 56 views

Hey Plastik Magazine readers! Ever feel like algebra is a secret code? Well, today, we're cracking that code by diving into the world of simplifying algebraic expressions. We'll be looking at some examples and breaking down how to make these expressions less intimidating and a whole lot easier to work with. So, grab your notebooks, and let's get started! We'll start by tackling some of the expressions given to us, and remember, the goal is always to make these problems simple and understandable, so no worries if you're a beginner; this is for everyone!

Simplifying 2x−618−6x\frac{2x - 6}{18 - 6x}

Alright, guys, let's kick things off with our first expression: 2x−618−6x\frac{2x - 6}{18 - 6x}. The name of the game here is factoring. We're looking for common factors in both the numerator (the top part) and the denominator (the bottom part). Think of it like a treasure hunt; we're trying to find something that both sides have in common so we can simplify the expression.

First, focus on the numerator, 2x−62x - 6. Can we factor out anything? Absolutely! Both terms have a common factor of 2. So, we rewrite it as 2(x−3)2(x - 3). Now, let's look at the denominator, 18−6x18 - 6x. Again, we can see a common factor of 6. Factoring that out gives us 6(3−x)6(3 - x). So now our expression looks like this: 2(x−3)6(3−x)\frac{2(x - 3)}{6(3 - x)}.

Now, here comes the clever part! Notice (x−3)(x - 3) and (3−x)(3 - x) look almost the same, but they're off by a sign. This is where a little trick comes in handy. Remember that (3−x)(3 - x) is the same as −(x−3)-(x - 3). Let's rewrite the denominator using this trick: 6(3−x)=6(−(x−3))=−6(x−3)6(3 - x) = 6(-(x - 3)) = -6(x - 3). Now our expression is 2(x−3)−6(x−3)\frac{2(x - 3)}{-6(x - 3)}.

See that (x−3)(x - 3) in both the numerator and the denominator? We can cancel those out! This leaves us with 2−6\frac{2}{-6}. Finally, simplify the fraction: 2−6=−13\frac{2}{-6} = -\frac{1}{3}. And that, my friends, is our simplified expression! This wasn't too bad, right? We simply found what was common, factored, and then simplified. Keep this approach in mind because it will come in handy when doing more complicated problems. Let's get to the next one!

Simplifying 8a2+10ab12a+15b\frac{8a^2 + 10ab}{12a + 15b}

Alright, let's move on to the second expression: 8a2+10ab12a+15b\frac{8a^2 + 10ab}{12a + 15b}. Remember our goal: factor and simplify. We will go step by step to solve this one. This time we have two variables in our expression, but don't panic; the steps are the same.

Let's start with the numerator, 8a2+10ab8a^2 + 10ab. Here, we can factor out a common factor of 2a2a. Doing so, we get 2a(4a+5b)2a(4a + 5b). Now, let's look at the denominator, 12a+15b12a + 15b. Here, the common factor is 3. Factoring that out, we get 3(4a+5b)3(4a + 5b).

So our expression now looks like this: 2a(4a+5b)3(4a+5b)\frac{2a(4a + 5b)}{3(4a + 5b)}. Can you spot anything we can cancel? Absolutely! We have (4a+5b)(4a + 5b) in both the numerator and the denominator. Cancel those out, and we're left with 2a3\frac{2a}{3}.

And that's our simplified expression! See, the same principles apply, even with a little more going on. Just keep your eyes peeled for those common factors, factor them out, and simplify. Easy peasy!

Simplifying x+4x2+9x+20\frac{x + 4}{x^2 + 9x + 20}

Okay, let's take on the third expression: x+4x2+9x+20\frac{x + 4}{x^2 + 9x + 20}. This one introduces a quadratic expression in the denominator, but don't sweat it. The process is still the same: factor and simplify. First, let's see if we can factor the numerator, x+4x + 4. Nope, not much we can do there. It's already in its simplest form. So we can move on to the denominator.

The denominator, x2+9x+20x^2 + 9x + 20, is a quadratic expression. To factor this, we need to find two numbers that multiply to 20 (the constant term) and add up to 9 (the coefficient of the x term). These numbers are 4 and 5, because 4*5 = 20 and 4 + 5 = 9. So, we can factor the denominator as (x+4)(x+5)(x + 4)(x + 5).

Now our expression is x+4(x+4)(x+5)\frac{x + 4}{(x + 4)(x + 5)}. Do you see what's coming? That's right, we can cancel out the (x+4)(x + 4) terms in the numerator and the denominator, leaving us with 1x+5\frac{1}{x + 5}. That's our simplified expression! Remember that when you cancel the entire term in the numerator, it leaves behind a 1, not 0.

Simplifying x2+6x−77x−7\frac{x^2 + 6x - 7}{7x - 7}

Alright, let's tackle x2+6x−77x−7\frac{x^2 + 6x - 7}{7x - 7}. This time, both the numerator and denominator need some work. Let's start with the numerator, x2+6x−7x^2 + 6x - 7. We need to find two numbers that multiply to -7 and add up to 6. Those numbers are 7 and -1 (7 * -1 = -7 and 7 + -1 = 6). So we can factor the numerator as (x+7)(x−1)(x + 7)(x - 1).

Now, let's look at the denominator, 7x−77x - 7. We can factor out a 7, giving us 7(x−1)7(x - 1). So our expression now looks like (x+7)(x−1)7(x−1)\frac{(x + 7)(x - 1)}{7(x - 1)}.

Can you spot the common factor? Bingo! We have (x−1)(x - 1) in both the numerator and the denominator. Canceling those out, we get x+77\frac{x + 7}{7}. That's our simplified expression. This is starting to become second nature, isn't it?

Simplifying 3x2−12xx2−6x+8\frac{3x^2 - 12x}{x^2 - 6x + 8}

Let's keep the ball rolling with 3x2−12xx2−6x+8\frac{3x^2 - 12x}{x^2 - 6x + 8}. Let's begin with the numerator, 3x2−12x3x^2 - 12x. We can factor out a 3x3x, which gives us 3x(x−4)3x(x - 4). Now, let's focus on the denominator, x2−6x+8x^2 - 6x + 8. We need to find two numbers that multiply to 8 and add up to -6. Those numbers are -2 and -4, since (-2 * -4 = 8 and -2 + -4 = -6). So the factored form of the denominator is (x−2)(x−4)(x - 2)(x - 4).

Now our expression is 3x(x−4)(x−2)(x−4)\frac{3x(x - 4)}{(x - 2)(x - 4)}. See that (x−4)(x - 4) in both the numerator and denominator? Let's cancel it out! We're left with 3xx−2\frac{3x}{x - 2}. And that's our simplified form. We are getting better at this!

Simplifying x2+6x−16x2+11x+24\frac{x^2 + 6x - 16}{x^2 + 11x + 24}

Finally, we'll finish with x2+6x−16x2+11x+24\frac{x^2 + 6x - 16}{x^2 + 11x + 24}. Both numerator and denominator are quadratic expressions, so let's get factoring!

For the numerator, x2+6x−16x^2 + 6x - 16, we need two numbers that multiply to -16 and add up to 6. Those numbers are 8 and -2. This means our factored numerator is (x+8)(x−2)(x + 8)(x - 2).

For the denominator, x2+11x+24x^2 + 11x + 24, we need two numbers that multiply to 24 and add up to 11. Those numbers are 8 and 3. So the factored denominator is (x+8)(x+3)(x + 8)(x + 3).

Our expression now looks like (x+8)(x−2)(x+8)(x+3)\frac{(x + 8)(x - 2)}{(x + 8)(x + 3)}. Can you see the common factor? That's right, we can cancel out the (x+8)(x + 8) terms. This leaves us with x−2x+3\frac{x - 2}{x + 3}. And there you have it, the final simplified expression! Congratulations; you made it to the end!

Conclusion: Mastering Simplification

So, there you have it, guys! We have simplified several algebraic expressions. The key takeaways are to always look for common factors, factor them out, and then cancel. Remember that practice makes perfect. Keep working through these problems, and soon you'll be simplifying expressions like a pro. Keep learning, and have fun doing it! Thanks for reading and see you next time. And don't forget to visit Plastik Magazine again for more cool content!