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

a. $(v+10)(v-10)$ b. $(s+4)(s-4)$
a. $v^{2}-100=$ ...rewrite $100$ as a square. $=v^{2}-10^{2}$ ...factor using the rule for a difference of two squares. ($a^{2}-b^{2}=(a+b)(a-b),\ a=v,\ b=10$) $=(v+10)(v-10)$ b. $s^{2}-16=$ ...rewrite $16$ as a square. $=s^{2}-4^{2}$ ...factor using the rule for a difference of two squares. ($a^{2}-b^{2}=(a+b)(a-b),\ a=s,\ b=4$) $=(s+4)(s-4)$