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Mathematics 16 Online
OpenStudy (jenniferjuice):

Factor completely 49x2 - 81. (7x + 9)2 (7x - 9)2 (7x + 9)(7x - 9) 7x - 9

OpenStudy (anonymous):

do you know what the square root of -81 is?

OpenStudy (anonymous):

or rather just the square root of 81

OpenStudy (jenniferjuice):

9

OpenStudy (anonymous):

good now what signs do you need to multiply to get to -81? ++ -- +-

OpenStudy (jenniferjuice):

+-

OpenStudy (anonymous):

yep. now what is the square root of 49?

OpenStudy (jenniferjuice):

7

OpenStudy (anonymous):

yep and the square root of a^2?

OpenStudy (anonymous):

sorry x^2

OpenStudy (jenniferjuice):

:/ mm idk

OpenStudy (anonymous):

that is x*x so the square root of that is just x

OpenStudy (anonymous):

so you have (7x + 9)(7x-9)

OpenStudy (jenniferjuice):

so c

OpenStudy (anonymous):

yep

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