Expand & Simplify: X * 4 * (2x + 3y)^2 - Explained!

by Faj Lennon 52 views

Hey guys! Let's break down how to expand and simplify the expression x * 4 * (2x + 3y)^2. This kind of problem often pops up in algebra, and mastering it can really boost your math skills. We’ll take it step by step, so it's super easy to follow. Let's get started!

Understanding the Basics

Before we dive into the full expression, let’s touch on some essential concepts. When we talk about "expanding," we mean getting rid of those parentheses by multiplying terms out. "Simplifying" means tidying up the expression by combining like terms.

Order of Operations

Remember PEMDAS or BODMAS? It's crucial. First, we handle Parentheses (or Brackets), then Exponents (or Orders), followed by Multiplication and Division (from left to right), and finally Addition and Subtraction (from left to right). This order ensures we solve expressions correctly every time.

Expanding Squares

The term (2x + 3y)^2 means (2x + 3y) * (2x + 3y). We need to use the FOIL method (First, Outer, Inner, Last) or the distributive property to expand this correctly.

Step-by-Step Expansion and Simplification

Now, let’s tackle the expression x * 4 * (2x + 3y)^2 step-by-step. This will make it super clear and manageable.

Step 1: Expand the Square

First, we need to expand (2x + 3y)^2. This means multiplying (2x + 3y) by itself:

(2x + 3y) * (2x + 3y)

Using the FOIL method:

  • First: 2x * 2x = 4x^2
  • Outer: 2x * 3y = 6xy
  • Inner: 3y * 2x = 6xy
  • Last: 3y * 3y = 9y^2

So, (2x + 3y)^2 = 4x^2 + 6xy + 6xy + 9y^2. Combine those like terms (the 'xy' terms):

(2x + 3y)^2 = 4x^2 + 12xy + 9y^2

Step 2: Multiply by 4

Next, we multiply the expanded square by 4:

4 * (4x^2 + 12xy + 9y^2)

Distribute the 4 across each term inside the parentheses:

4 * 4x^2 = 16x^2 4 * 12xy = 48xy 4 * 9y^2 = 36y^2

So, 4 * (4x^2 + 12xy + 9y^2) = 16x^2 + 48xy + 36y^2

Step 3: Multiply by x

Now, we multiply the entire expression by x:

x * (16x^2 + 48xy + 36y^2)

Distribute the x across each term:

x * 16x^2 = 16x^3 x * 48xy = 48x^2y x * 36y^2 = 36xy^2

So, x * (16x^2 + 48xy + 36y^2) = 16x^3 + 48x^2y + 36xy^2

Final Result

Therefore, the expanded and simplified form of x * 4 * (2x + 3y)^2 is:

16x^3 + 48x^2y + 36xy^2

Common Mistakes to Avoid

Let's look at some common pitfalls people encounter when tackling these problems. Steering clear of these will save you a lot of headaches.

Forgetting the Order of Operations

It’s super easy to mess up if you don’t follow PEMDAS/BODMAS. Always handle exponents before multiplication.

Incorrectly Expanding Squares

A common mistake is thinking (2x + 3y)^2 = 4x^2 + 9y^2. Remember, you need to account for the cross terms (2x * 3y and 3y * 2x).

Distributing Negatives

Be extra careful when distributing a negative sign. Make sure every term inside the parentheses gets affected.

Practice Problems

Want to really nail this down? Here are a few practice problems to try out.

  1. Expand and simplify: 2x * (x - 4y)^2
  2. Expand and simplify: 3 * (2a + b)^2 * a
  3. Expand and simplify: y * 5 * (x + 2y)^2

Work through these, and you’ll become a pro in no time!

Tips for Success

Here are some extra tips to help you succeed when expanding and simplifying expressions:

Write Neatly

Keep your work organized. A neat layout helps you avoid mistakes and makes it easier to review your steps.

Double-Check Your Work

Always go back and check each step. It’s easy to make a small error, and catching it early can save you a lot of trouble.

Practice Regularly

The more you practice, the better you’ll get. Regular practice builds confidence and helps you recognize patterns.

Use Online Tools

There are tons of online calculators and tools that can help you check your work. Use them to verify your answers, but don’t rely on them to do the work for you.

Real-World Applications

You might be wondering, "Where will I ever use this in real life?" Well, expanding and simplifying expressions comes in handy in various fields.

Engineering

Engineers use algebraic expressions to model and solve problems in structural analysis, circuit design, and more.

Physics

In physics, you’ll encounter these skills when working with equations of motion, energy, and other concepts.

Computer Science

Computer programmers use algebraic manipulation in algorithm design and optimization.

Economics

Economists use equations to model market behavior, and simplifying these equations can provide valuable insights.

Conclusion

So, there you have it! Expanding and simplifying expressions like x * 4 * (2x + 3y)^2 might seem daunting at first, but with a step-by-step approach and a solid understanding of the basics, you can master it. Remember to follow the order of operations, avoid common mistakes, and practice regularly. Keep up the great work, and you’ll be acing those algebra problems in no time! Happy math-ing, guys!