Answer
$a^{2} - 36b^{2}$
Work Step by Step
We use the formula for the difference of squares to apply to this question.
The difference of squares formula is:
$(a-b) (a+b) = a^{2} - b^{2}$
In the given formula let a represents a and 6b represents b.
$(a-6b) (a+6b) = a^{2} - (6b)^{2}$
= $a^{2} - 36b^{2}$
