Factoring Difference of Squares and Perfect Square Trinomials

The difference of squares formula states that $$a^2 - b^2 = (a - b)(a + b)$$ .

$$(x + 4)(x - 4)$$ .

A perfect square trinomial is an expression of the form $$a^2 + 2ab + b^2$$ or $$a^2 - 2ab + b^2$$ , which factors to $$(a + b)^2$$ or $$(a - b)^2$$ .

$$(x + 3)(x - 3)$$ .

Identify the two perfect squares in the expression and apply the difference of squares formula.

$$5(3x + 2)(3x - 2)$$ .

The general form is $$a^2 + 2ab + b^2$$ or $$a^2 - 2ab + b^2$$ .

$$(8x - 9)(8x + 9)$$ .

An expression is factorable if it can be expressed as a product of two or more factors.

$$3(x + 5)(x - 5)$$ .