6x +9 = +32 x2 + x2 + 2∙3∙x = (x + 3)2 4x2 20x + 25 = (2x)2 2∙2x∙5 + 52 – – = (2x 5)2 – Factoring (Difference of Squares) a2 b2 = (a + b)(a b) – – Examples: 49 = 72 = (x + 7)(x 7) x2 x2 – – –
x2 + 6x +9 = x2 + 2∙3∙x +32 = (x + 3)2 4x2 – 20x + 25 = (2x)2 – 2∙2x∙5 + 52 = (2x – 5)2 Factoring (Difference of Squares) a2 – b2 = (a + b)(a – b) Examples: x2 – 49 = x2 – 72 = (x + 7)(x – 7)