Answer
a. $(5d+8)(5d-8)$
b. No, because $25d^{2}+64$ is not a difference of squares.
Work Step by Step
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.
