Verify the Equality: (x+8)(x-4) = (x-8)(x+4)

Polynomial Expansion with Coefficient Comparison

Is equality correct?

(x+8)(x4)=(x8)(x+4) (x+8)(x-4)=(x-8)(x+4)

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Are the expressions equal?
00:03 Open parentheses properly, multiply each factor by each factor
00:21 Calculate the products
00:34 Collect terms
00:42 Use the same method and simplify the other side
00:53 Open parentheses properly, multiply each factor by each factor
01:06 Calculate the products and collect terms
01:24 Compare the terms of the expressions, we see they are different
01:28 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Is equality correct?

(x+8)(x4)=(x8)(x+4) (x+8)(x-4)=(x-8)(x+4)

2

Step-by-step solution

To determine if the equation (x+8)(x4)=(x8)(x+4)(x+8)(x-4) = (x-8)(x+4) is true, we'll need to expand both sides and compare their forms.

We begin with the left-hand side:

  • (x+8)(x4)(x+8)(x-4)

  • Expanding using the distributive property, we get:

  • xx+x(4)+8x+8(4)x \cdot x + x \cdot (-4) + 8 \cdot x + 8 \cdot (-4)

  • This simplifies to x24x+8x32x^2 - 4x + 8x - 32

  • Further simplification gives x2+4x32x^2 + 4x - 32

Now, let's examine the right-hand side:

  • (x8)(x+4)(x-8)(x+4)

  • Expanding using the distributive property, we obtain:

  • xx+x48x84x \cdot x + x \cdot 4 - 8 \cdot x - 8 \cdot 4

  • This simplifies to x2+4x8x32x^2 + 4x - 8x - 32

  • Further simplification yields x24x32x^2 - 4x - 32

Next, compare the results:

The left-hand side is x2+4x32x^2 + 4x - 32, while the right-hand side is x24x32x^2 - 4x - 32.

Note that the coefficients of the xx terms are different:

  • On the left: The coefficient of xx is +4+4.

  • On the right: The coefficient of xx is 4-4.

Since the coefficients ofxx differ, the two expressions are not equal.

Therefore, the equality (x+8)(x4)=(x8)(x+4)(x+8)(x-4) = (x-8)(x+4) is not correct.

The correct answer to this problem is No, the coefficients of x x in contrasting expressions.

3

Final Answer

No, the coefficients of x x In contrasting expressions

Key Points to Remember

Essential concepts to master this topic
  • Expansion Rule: Use distributive property to multiply each term systematically
  • Technique: (x+8)(x4)=x2+4x32 (x+8)(x-4) = x^2 + 4x - 32 vs (x8)(x+4)=x24x32 (x-8)(x+4) = x^2 - 4x - 32
  • Check: Compare coefficients term by term: x2 x^2 , x x , and constant terms ✓

Common Mistakes

Avoid these frequent errors
  • Assuming expressions are equal without expanding
    Don't just look at the structure and assume equality = wrong conclusion! The order of terms matters when multiplying. Always expand both expressions completely and compare each coefficient.

Practice Quiz

Test your knowledge with interactive questions

\( (3+20)\times(12+4)= \)

FAQ

Everything you need to know about this question

Why can't I just rearrange the terms to make them equal?

+

You cannot rearrange factors in a product! (x+8)(x4) (x+8)(x-4) and (x8)(x+4) (x-8)(x+4) are completely different expressions that expand to different polynomials.

How do I expand binomial products correctly?

+

Use FOIL method: First terms, Outer terms, Inner terms, Last terms. For example: (x+8)(x4)=x24x+8x32 (x+8)(x-4) = x^2 - 4x + 8x - 32 .

What should I compare after expanding?

+

Compare each coefficient separately: the x2 x^2 coefficient, the x x coefficient, and the constant term. All three must match for equality.

Why are the x coefficients different here?

+

Left side: 4x+8x=+4x -4x + 8x = +4x . Right side: +4x8x=4x +4x - 8x = -4x . The order of the constants (8 vs -8, -4 vs +4) creates opposite signs!

Can two different expressions ever be equal for all x values?

+

Only if they're identical after expanding! If any coefficient differs, the expressions are equal only for specific x values, not for all x values.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Algebraic Technique questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations