Find The Missing Coefficient: A Math Puzzle!

by Sebastian Müller 45 views

Have you ever stumbled upon a math problem that looks like a puzzle with a missing piece? Well, you're not alone! Today, we're diving into one of those intriguing problems: finding a missing coefficient in a polynomial expression. This might sound intimidating, but trust me, it's totally manageable. We'll break it down step-by-step, making it super easy to understand. So, grab your thinking caps, and let's get started!

Understanding the Problem

The problem we're tackling today looks like this:

(15x² + 11y² + 8x) - (7x² + 5y² + 2x) = □x² + 6y² + 6x

Our mission, should we choose to accept it (and we totally do!), is to figure out what number goes in that little square box – the missing coefficient of the x² term. This kind of problem is a classic example of algebraic manipulation, where we use the rules of algebra to simplify expressions and solve for unknowns. Don't worry if you're not an algebra whiz just yet; we'll walk through each step together.

Think of it like this: we have two groups of terms (polynomials, to be precise) that are being subtracted. When we subtract these groups, we get a new group of terms. One of the terms in this new group has a missing number in front of it, and that's what we need to find. It’s like a mathematical detective story, and we're the detectives!

Before we jump into the solution, let's make sure we're all on the same page with some basic concepts. Polynomials are expressions that consist of variables (like x and y) raised to different powers, along with coefficients (the numbers in front of the variables) and constants (numbers without variables). In our problem, we have terms like 15x², 11y², 8x, and so on. The coefficients are 15, 11, 8, and so on. Understanding these building blocks is crucial for solving the problem.

Now, when we subtract polynomials, we're essentially combining like terms. Like terms are those that have the same variable raised to the same power. For example, 15x² and 7x² are like terms because they both have x²; 11y² and 5y² are like terms because they both have y²; and 8x and 2x are like terms because they both have x. We can only add or subtract like terms, just like we can only add apples to apples and oranges to oranges. This is a fundamental rule in algebra, and it's the key to unlocking this problem. So, with our understanding of polynomials and like terms in place, we're ready to roll up our sleeves and dive into the solution!

Step-by-Step Solution

Okay, guys, let's get our hands dirty and solve this thing! Here’s how we can find the missing coefficient, step-by-step:

1. Distribute the Negative Sign

First things first, we need to deal with the subtraction sign in front of the second set of parentheses. Remember, subtracting a group of terms is the same as adding the opposite of each term inside the parentheses. So, we distribute the negative sign to each term in the second set of parentheses:

(15x² + 11y² + 8x) - (7x² + 5y² + 2x) becomes 15x² + 11y² + 8x - 7x² - 5y² - 2x

Think of it like this: the minus sign is like a little ninja that sneaks in and changes the sign of everything inside the parentheses. A positive becomes a negative, and a negative becomes a positive. It's a crucial step because it sets us up to combine like terms correctly.

2. Combine Like Terms

Now comes the fun part – combining those like terms! Remember, like terms have the same variable raised to the same power. Let's group them together:

  • x² terms: 15x² - 7x²
  • y² terms: 11y² - 5y²
  • x terms: 8x - 2x

Now, we simply add or subtract the coefficients of these like terms:

  • 15x² - 7x² = 8x²
  • 11y² - 5y² = 6y²
  • 8x - 2x = 6x

Combining like terms is like sorting your laundry. You wouldn't throw your socks in with your shirts, would you? Similarly, we keep the x² terms together, the y² terms together, and the x terms together. This makes the expression much simpler and easier to manage. It's like tidying up a messy room – everything is in its place, and we can see the structure more clearly.

3. Write the Simplified Expression

Now that we've combined like terms, let's put everything together to form our simplified expression:

8x² + 6y² + 6x

Ta-da! We've simplified the original expression into a much cleaner and more manageable form. This is a crucial step because it allows us to directly compare our result with the expression given in the problem, which has the missing coefficient.

4. Identify the Missing Coefficient

Now, let's compare our simplified expression with the expression given in the problem:

Our simplified expression: 8x² + 6y² + 6x

Problem's expression: □x² + 6y² + 6x

Notice anything? The y² and x terms match perfectly! The only difference is the coefficient of the x² term. In our simplified expression, the coefficient of x² is 8. In the problem's expression, it's represented by the square box – our missing coefficient!

Therefore, the missing coefficient is 8.

And that's it! We've cracked the case and found the missing piece of the puzzle. By carefully distributing the negative sign, combining like terms, and comparing expressions, we were able to identify the missing coefficient. It's like being a math detective, piecing together the clues to solve the mystery. This process highlights the power of algebraic manipulation in simplifying expressions and solving for unknowns. So, give yourself a pat on the back – you've successfully navigated this algebraic challenge!

Why This Matters

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