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 Question from Rosa, a student: Can 100r^2-81z^2 be factored?

Hi Rosa,

100 is 10 squared and 81 is 9 squared so $100r^2-81z^2$ can be written

$\left(10 r\right)^2 - \left(9 z\right)^2$

Now can you factor it?
Penny

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