Blahblah: Factor the given polynomial
x^2-17x+72
You need to look for 2 numbers that multiply to 72 and add to -17
Think about the multiply one first.
In order to mult to give a positive number, they both must be neg or they both must be positive
however, the add to give a negative so they both must be negative!
What are the factor pairs of 72
-72,-1 They dont add to -17
-36,-2 no they don't add to -17 either
-9 and -8 They do add to -17 BINGO!
the answer is
(x-9)(x-8)
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Hi BlahBlah,
I was think about doing some of these on a general information post.
Do you think that a lot of students have problems with them ?
Do you think that would be a good idea?
Would you be prepared to answer some questions that I put on such a post?
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