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How can i factor this? 49-x^2-6xy-9y^2 i tried to group them in different ways but i...
How can i factor this? 49-x^2-6xy-9y^2
i tried to group them in different ways but i still can't get the answer which is -(x+3y+7)(x+3y-7) i think i've done something wrong but can't find out what it is so if anyone can please help coz i've been stuck in this problem for 25 minutes and i still have to do 12 problems thank you :D
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High School Teacher
Factor `49-x^2-6xy-9y^2` :
Write as `49-(x^2+6xy+9y^2)`
The terms in the parantheses form a perfect square trinomial.
`=49-[(x+3y)^2]` But this is the difference of two squares:
`=(7+x+3y)(7-x-3y)` Factoring a (-1) out of the second factor gets the answer in the form you were seeking:
Posted by embizze on November 19, 2012 at 2:20 AM (Answer #1)
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