Factor the given polynomials using difference of squares.

Binomial: 9x^2 - 25
Binomial: 9 - 25x^2
Binomial: 4x^2 -36
Binomial: 81-49x^2
Binomial: 81x^2 -49
Binomial: 4x^2 + 36

1 answer

To factor the given polynomials using the difference of squares, we can use the formula \( a^2 - b^2 = (a - b)(a + b) \).

Let's factor each binomial step by step:

  1. Binomial: \( 9x^2 - 25 \)
    Here, \( a^2 = 9x^2 \) and \( b^2 = 25 \).
    Thus, \( a = 3x \) and \( b = 5 \).
    Factored form:
    \[ 9x^2 - 25 = (3x - 5)(3x + 5) \]

  2. Binomial: \( 9 - 25x^2 \)
    Here, \( a^2 = 9 \) and \( b^2 = 25x^2 \).
    Thus, \( a = 3 \) and \( b = 5x \).
    Factored form:
    \[ 9 - 25x^2 = (3 - 5x)(3 + 5x) \]

  3. Binomial: \( 4x^2 - 36 \)
    Here, \( a^2 = 4x^2 \) and \( b^2 = 36 \).
    Thus, \( a = 2x \) and \( b = 6 \).
    Factored form:
    \[ 4x^2 - 36 = (2x - 6)(2x + 6) \] We can further factor it using \( 2 \) as a common factor:
    \[ = 2(2x - 6)(2x + 6) = 2(2(x - 3))(2(x + 3)) = 4(x - 3)(x + 3) \]

  4. Binomial: \( 81 - 49x^2 \)
    Here, \( a^2 = 81 \) and \( b^2 = 49x^2 \).
    Thus, \( a = 9 \) and \( b = 7x \).
    Factored form:
    \[ 81 - 49x^2 = (9 - 7x)(9 + 7x) \]

  5. Binomial: \( 81x^2 - 49 \)
    Here, \( a^2 = 81x^2 \) and \( b^2 = 49 \).
    Thus, \( a = 9x \) and \( b = 7 \).
    Factored form:
    \[ 81x^2 - 49 = (9x - 7)(9x + 7) \]

  6. Binomial: \( 4x^2 + 36 \)
    This is a sum of squares, not a difference, and cannot be factored using the difference of squares formula. So, it is already in its simplest form.

In summary, the factored forms for the provided binomials are:

  1. \( 9x^2 - 25 = (3x - 5)(3x + 5) \)
  2. \( 9 - 25x^2 = (3 - 5x)(3 + 5x) \)
  3. \( 4x^2 - 36 = 4(x - 3)(x + 3) \)
  4. \( 81 - 49x^2 = (9 - 7x)(9 + 7x) \)
  5. \( 81x^2 - 49 = (9x - 7)(9x + 7) \)
  6. \( 4x^2 + 36 \) cannot be factored using difference of squares.