SOLUTION: How do I completely factor the following expression 81y^2 - 4z^2

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Question 492056: How do I completely factor the following expression 81y^2 - 4z^2
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Since:
81y^2 - 4z^2
can be rewritten as:
(9y)^2 - (2z)^2
This is a "difference of squares" (special case):
(9y - 2z)(9y + 2z)