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anonymous
 4 years ago
how can i factor this out?
28b^280b128
anonymous
 4 years ago
how can i factor this out? 28b^280b128

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mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1First ask yourself if there is a constant you can factor out of all the coefficients. :)

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Yup. So now write 4 times (whatever is left over after you factor out 4)

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.04(7b^220b32) but then what do i do?

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Now we want to factor out 7b^220b32 into the product of two binomaisl: (b plus or minus stuff) times ( b plus or minus stuff). BUT LOOK! The coefficient of b^2 is 7, so that means we automatically know that it's going to look like... (7b plus or minus stuff) times (b plus or minus stuff).

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0well that is where i'm confused

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0how do i know what number to choose?

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Can you factor something like: x^2 + 10x +21 ? It's similar to that, but just a little harder.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0but if i factor out 32 there is nothing that would match 20

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0is there anything i can do?

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1The answer to this problem is the same as factoring something like x^2 + 10x +21 Describe how you would factor this and then the solution to your problem will make much more sense. :)

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Yes! :) How did you obtain that answer? How did you know to go for +7 and +3? Also, can you factor: x^2 4x 21

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0well because the numbers are positive But i'm confused w/ my original problem

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.17b^220b32 = (7b ) * ( b ) The two numbers you fill in will have to multiply to negative 32. That's the start of it.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0right but there is 1*32,2*16,4*8

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1You have to try those out. :) ALSO note how one of those numbers is gonna be multplied by 7 when you FOIL. So it's trial and error. After a bit of practice you develop a number sense about these things. So for instance 1 * 32 won't work... (7b +32)(b 1) FOIL that out and you get 7b^2 32b 7b = 25b 31 So try the next one...

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1In what order? And with what signs (which is + and which is  ) ?

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Let's factor that out now: (7b4)(b+8) 7b^2 (good) 4b +56b = 52b (nope) 8 * 4 = 32 (good)

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1You are VERY close though!

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0i don't know where to go from there

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1No, because 1 * 2 = 2. You were right, it's 4 and 8. But the order and the sign need to be tweaked.

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1(7b )(b ) Fill in the blanks with 4 and 8. One of the combinations will work. :)

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Do you know how to FOIL? (or expand) a binomial? That is the other half of solving problems like these. Going from (7b +4)(b +8) to 7b^2 +12b +32 is critical to the trialanderror portion.

mathteacher1729
 4 years ago
Best ResponseYou've already chosen the best response.1Paul's Online Math Notes has a very nice explanation of this with TONS of examples: http://tutorial.math.lamar.edu/Classes/Alg/Factoring.aspx I have to sign off, but hopefully this will help a little. :)
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