Mastering Algebraic Simplification: A Guide

by Andrew McMorgan 44 views

Hey Plastik Magazine readers! Let's dive into the world of algebra and make simplifying those tricky expressions a breeze. In this guide, we'll break down how to simplify several algebraic expressions. Get ready to flex your math muscles and learn some cool tricks along the way! We'll tackle each expression step-by-step, making sure you understand every move. Ready? Let's go!

Simplifying the Expression: 6x2+3x4x2−1\frac{6x^2 + 3x}{4x^2 - 1}

Alright, guys, let's start with our first expression: 6x2+3x4x2−1\frac{6x^2 + 3x}{4x^2 - 1}. Our goal here is to simplify this fraction as much as possible. This involves factoring both the numerator (the top part) and the denominator (the bottom part) and then canceling out any common factors. Think of it like a puzzle where we're trying to find the matching pieces.

First, let's look at the numerator, 6x2+3x6x^2 + 3x. See something in common? Yep, both terms have a common factor of 3x3x. We can factor this out: 3x(2x+1)3x(2x + 1). So, the numerator simplifies to 3x(2x+1)3x(2x + 1). Not bad, right?

Now, let's move on to the denominator, 4x2−14x^2 - 1. This is a classic case of the difference of squares! Remember the formula: a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b)? Here, 4x24x^2 is (2x)2(2x)^2 and 11 is 121^2. So, we can factor the denominator as (2x−1)(2x+1)(2x - 1)(2x + 1).

Now we have 3x(2x+1)(2x−1)(2x+1)\frac{3x(2x + 1)}{(2x - 1)(2x + 1)}. See that (2x+1)(2x + 1) in both the numerator and the denominator? Bingo! We can cancel these out, leaving us with 3x2x−1\frac{3x}{2x - 1}. That's our simplified expression. We took a complex-looking fraction and turned it into something much cleaner. Awesome, right? Keep practicing, and you'll become a simplification pro in no time! Remember, the key is to spot those common factors and apply the right factoring techniques.

Step-by-Step Breakdown

  1. Factor the Numerator: 6x2+3x=3x(2x+1)6x^2 + 3x = 3x(2x + 1). Identify the greatest common factor (GCF), which is 3x3x.
  2. Factor the Denominator: 4x2−1=(2x−1)(2x+1)4x^2 - 1 = (2x - 1)(2x + 1). Recognize this as a difference of squares.
  3. Rewrite the Expression: 3x(2x+1)(2x−1)(2x+1)\frac{3x(2x + 1)}{(2x - 1)(2x + 1)}.
  4. Cancel Common Factors: Cancel out (2x+1)(2x + 1).
  5. Simplified Expression: 3x2x−1\frac{3x}{2x - 1}.

Simplifying the Expression: x2−8x+152x2−7x−15\frac{x^2 - 8x + 15}{2x^2 - 7x - 15}

Alright, let's get our hands dirty with the next expression: x2−8x+152x2−7x−15\frac{x^2 - 8x + 15}{2x^2 - 7x - 15}. This one looks a bit more complicated, but don't worry, we'll break it down step by step. Our main strategy here is still factoring – we're going to factor both the numerator and the denominator and then see if we can cancel out any common factors. The key to success is careful observation and remembering those factoring techniques!

First, let's tackle the numerator, x2−8x+15x^2 - 8x + 15. This is a quadratic expression, and we want to find two numbers that multiply to 1515 and add up to −8-8. After some thought, we find that −3-3 and −5-5 fit the bill because (−3)∗(−5)=15(-3) * (-5) = 15 and (−3)+(−5)=−8(-3) + (-5) = -8. So, we can factor the numerator as (x−3)(x−5)(x - 3)(x - 5).

Now, for the denominator, 2x2−7x−152x^2 - 7x - 15, things get a little trickier because of that 22 in front of the x2x^2. We can factor this by grouping or using the AC method. The AC method involves multiplying the coefficient of x2x^2 (which is 22) by the constant term (which is −15-15) to get −30-30. Then, we need to find two numbers that multiply to −30-30 and add up to −7-7. Those numbers are −10-10 and 33. We can rewrite the middle term of the denominator as −10x+3x-10x + 3x, and then factor by grouping.

So, 2x2−7x−152x^2 - 7x - 15 becomes 2x2−10x+3x−152x^2 - 10x + 3x - 15. Now, group the terms: (2x2−10x)+(3x−15)(2x^2 - 10x) + (3x - 15). Factor out the common factors from each group: 2x(x−5)+3(x−5)2x(x - 5) + 3(x - 5). Notice that we now have a common factor of (x−5)(x - 5). Factor it out to get (x−5)(2x+3)(x - 5)(2x + 3).

So, we now have (x−3)(x−5)(x−5)(2x+3)\frac{(x - 3)(x - 5)}{(x - 5)(2x + 3)}. See that (x−5)(x - 5) in both the numerator and the denominator? Yes, we can cancel those out! This leaves us with x−32x+3\frac{x - 3}{2x + 3}. And there you have it, our simplified expression.

Step-by-Step Breakdown

  1. Factor the Numerator: x2−8x+15=(x−3)(x−5)x^2 - 8x + 15 = (x - 3)(x - 5). Find two numbers that multiply to 1515 and add up to −8-8.
  2. Factor the Denominator: 2x2−7x−15=(x−5)(2x+3)2x^2 - 7x - 15 = (x - 5)(2x + 3). Use factoring by grouping or the AC method.
  3. Rewrite the Expression: (x−3)(x−5)(x−5)(2x+3)\frac{(x - 3)(x - 5)}{(x - 5)(2x + 3)}.
  4. Cancel Common Factors: Cancel out (x−5)(x - 5).
  5. Simplified Expression: x−32x+3\frac{x - 3}{2x + 3}.

Simplifying the Expression: x2−92x2−7x+3\frac{x^2 - 9}{2x^2 - 7x + 3}

Let's keep the momentum going, fellas! Next up is x2−92x2−7x+3\frac{x^2 - 9}{2x^2 - 7x + 3}. This expression presents another great opportunity to flex our factoring skills. As before, our goal is to factor the numerator and the denominator, and then look for common factors that we can cancel out. Let's see what we can do!

Starting with the numerator, x2−9x^2 - 9, this looks familiar, doesn't it? It's another difference of squares! We can factor it using the formula a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b). Here, x2x^2 is x2x^2 and 99 is 323^2. So, we factor it into (x−3)(x+3)(x - 3)(x + 3). Easy peasy!

Now, let's move on to the denominator, 2x2−7x+32x^2 - 7x + 3. This is another quadratic expression, so we'll need to find factors that multiply to give us this expression. Since there's a 22 in front of the x2x^2, we can use the AC method or factoring by grouping. Let's find two numbers that multiply to 2∗3=62 * 3 = 6 and add up to −7-7. Those numbers are −6-6 and −1-1. So, we rewrite the middle term as −6x−x-6x - x.

Thus, 2x2−7x+32x^2 - 7x + 3 becomes 2x2−6x−x+32x^2 - 6x - x + 3. Now, we can factor by grouping. Group the terms: (2x2−6x)+(−x+3)(2x^2 - 6x) + (-x + 3). Factor out the common factors from each group: 2x(x−3)−1(x−3)2x(x - 3) - 1(x - 3). Notice that we now have a common factor of (x−3)(x - 3). Factor that out to get (x−3)(2x−1)(x - 3)(2x - 1).

So, now we have (x−3)(x+3)(x−3)(2x−1)\frac{(x - 3)(x + 3)}{(x - 3)(2x - 1)}. Guess what we can do? You got it! Cancel out the (x−3)(x - 3) term that appears in both the numerator and the denominator. This leaves us with x+32x−1\frac{x + 3}{2x - 1}. And that's our simplified expression. Great job, everyone! We're mastering this!

Step-by-Step Breakdown

  1. Factor the Numerator: x2−9=(x−3)(x+3)x^2 - 9 = (x - 3)(x + 3). Recognize and apply the difference of squares formula.
  2. Factor the Denominator: 2x2−7x+3=(x−3)(2x−1)2x^2 - 7x + 3 = (x - 3)(2x - 1). Use the AC method or factoring by grouping.
  3. Rewrite the Expression: (x−3)(x+3)(x−3)(2x−1)\frac{(x - 3)(x + 3)}{(x - 3)(2x - 1)}.
  4. Cancel Common Factors: Cancel out (x−3)(x - 3).
  5. Simplified Expression: x+32x−1\frac{x + 3}{2x - 1}.

Simplifying the Expression: 6x2−x−14x2−1\frac{6x^2 - x - 1}{4x^2 - 1}

Alright, we're on the home stretch! Let's simplify 6x2−x−14x2−1\frac{6x^2 - x - 1}{4x^2 - 1}. This expression is a great way to put all our skills together. Remember, the key is to be methodical and break down each part of the fraction. Let's go!

First, let's factor the numerator, 6x2−x−16x^2 - x - 1. This is another quadratic expression, and we'll use the AC method (or factoring by grouping) to factor it. We need to find two numbers that multiply to 6∗−1=−66 * -1 = -6 and add up to −1-1. Those numbers are −3-3 and 22. So, we rewrite the middle term as −3x+2x-3x + 2x.

Thus, 6x2−x−16x^2 - x - 1 becomes 6x2−3x+2x−16x^2 - 3x + 2x - 1. Now, we can factor by grouping. Group the terms: (6x2−3x)+(2x−1)(6x^2 - 3x) + (2x - 1). Factor out the common factors from each group: 3x(2x−1)+1(2x−1)3x(2x - 1) + 1(2x - 1). Notice that we now have a common factor of (2x−1)(2x - 1). Factor that out to get (2x−1)(3x+1)(2x - 1)(3x + 1).

Next, we'll factor the denominator, 4x2−14x^2 - 1. This is another example of the difference of squares. We can rewrite 4x24x^2 as (2x)2(2x)^2 and 11 as 121^2. Therefore, we can factor the denominator as (2x−1)(2x+1)(2x - 1)(2x + 1).

So, now we have (2x−1)(3x+1)(2x−1)(2x+1)\frac{(2x - 1)(3x + 1)}{(2x - 1)(2x + 1)}. See that (2x−1)(2x - 1) term? Yes, we can cancel it out from the numerator and the denominator, which leaves us with 3x+12x+1\frac{3x + 1}{2x + 1}. And there you have it – another expression simplified! Great work, team!

Step-by-Step Breakdown

  1. Factor the Numerator: 6x2−x−1=(2x−1)(3x+1)6x^2 - x - 1 = (2x - 1)(3x + 1). Use the AC method or factoring by grouping.
  2. Factor the Denominator: 4x2−1=(2x−1)(2x+1)4x^2 - 1 = (2x - 1)(2x + 1). Recognize and apply the difference of squares.
  3. Rewrite the Expression: (2x−1)(3x+1)(2x−1)(2x+1)\frac{(2x - 1)(3x + 1)}{(2x - 1)(2x + 1)}.
  4. Cancel Common Factors: Cancel out (2x−1)(2x - 1).
  5. Simplified Expression: 3x+12x+1\frac{3x + 1}{2x + 1}.

Conclusion

And that's a wrap, guys! You've successfully navigated the world of algebraic simplification. Remember, practice makes perfect! The more you work with these types of problems, the easier and more intuitive they'll become. Keep practicing, and you'll be simplifying expressions like a pro in no time. If you found this helpful, let us know in the comments below! Keep rocking the math, and stay awesome! Until next time!