Answer
a. $(v+10)(v-10)$
b. $(s+4)(s-4)$
Work Step by Step
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.
($a^{2}-b^{2}=(a+b)(a-b),\ a=s,\ b=4$)
$=(s+4)(s-4)$
