(x+3)(x-3)(x+4)(x-4)

2 min read Jun 16, 2024
(x+3)(x-3)(x+4)(x-4)

Expanding and Factoring the Expression (x+3)(x-3)(x+4)(x-4)

This expression involves a pattern that allows for efficient expansion and factorization:

The Difference of Squares Pattern:

The difference of squares pattern states that: (a + b)(a - b) = a² - b²

Applying the pattern to the expression:

Notice that the expression contains two pairs of factors that follow the difference of squares pattern:

  • (x + 3)(x - 3)
  • (x + 4)(x - 4)

Expanding the expression:

  1. First Pair: (x + 3)(x - 3) = x² - 3² = x² - 9

  2. Second Pair: (x + 4)(x - 4) = x² - 4² = x² - 16

  3. Combining the results: (x² - 9)(x² - 16)

  4. Expanding further: x⁴ - 16x² - 9x² + 144 = x⁴ - 25x² + 144

Factoring the expression back:

  1. Recognize the pattern: The expanded form (x⁴ - 25x² + 144) resembles a quadratic equation if we substitute y = x²: y² - 25y + 144

  2. Factor the quadratic: (y - 16)(y - 9)

  3. Substitute back: (x² - 16)(x² - 9)

  4. Apply the difference of squares pattern again: (x + 4)(x - 4)(x + 3)(x - 3)

Therefore, we have successfully expanded and factored the given expression. The final factored form is (x + 4)(x - 4)(x + 3)(x - 3).

Key takeaways:

  • The difference of squares pattern is a powerful tool for simplifying and factoring expressions.
  • Recognizing patterns in expressions helps streamline the expansion and factorization process.
  • By substituting variables, we can simplify expressions and make them easier to work with.

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