Chapter 1 - Section 1.3 - Algebraic Expressions - 1.3 Exercises - Page 34: 113

$(x+1)(x-1)(x+3)(x-3)$

$Factor$ $the$ $expression$ $completely:$ $x^2(x^2-1) - 9(x^2-1)$ Factor out $(x^2-1)$ from both terms $(x^2-1)(x^2-9)$ Use the Difference of Squares Formula for both binomials Difference of Squares Formula: $(A^2-B^2) = (A-B)(A+B)$ $(x^2-1) = (x+1)(x-1)$ $(x^2-9) = (x+3)(x-3)$ $= (x+1)(x-1)(x+3)(x-3)$