## Algebra 1: Common Core (15th Edition)

a. $(5d+8)(5d-8)$ b. No, because $25d^{2}+64$ is not a difference of squares.
a. $25d^{2}-64=$ ...write each term as a square. $=(5d)^{2}-8^{2}$ ...factor using the rule for a difference of two squares. ($a^{2}-b^{2}=(a+b)(a-b),\ a=5d,\ b=8$) $=(5d+8)(5d-8)$ b. No, you can not use the same method because $25d^{2}+64$ is not a difference of squares.