Question

which products result in a difference of squares or a perfect square trinomial? check all that apply.

\\((5x + 3)(5x - 3)\\)
\\((7x + 4)(7x + 4)\\)
\\((2x + 1)(x + 2)\\)
\\((4x - 6)(x + 8)\\)
\\((x - 9)(x - 9)\\)
\\((-3x - 6)(-3x + 6)\\)

Explanation:

Identify difference of squares products

Using the Difference of Squares knowledge point

$$ (a+b)(a-b) = a^2 - b^2 $$

$$
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$$

Identify perfect square trinomial products

Using the Perfect Square Trinomial knowledge point

$$ (a+b)^2 = a^2 + 2ab + b^2,\quad (a-b)^2 = a^2 - 2ab + b^2 $$

$$
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$$

Evaluate remaining products

Using the Polynomial Multiplication knowledge point

$$
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$$

Answer:

• (A) \((5x + 3)(5x - 3)\) (Correct answer)
• (B) \((7x + 4)(7x + 4)\) (Correct answer)
• (C) \((2x + 1)(x + 2)\)
• (D) \((4x - 6)(x + 8)\)
• (E) \((x - 9)(x - 9)\) (Correct answer)
• (F) \((-3x - 6)(-3x + 6)\) (Correct answer)