SOLUTION: Factoring Completely: How do you factor a problem like this: (x^2 + 10x + 21)

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Question 159230: Factoring Completely: How do you factor a problem like this: (x^2 + 10x + 21)

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Factoring Completely: How do you factor a problem like this: (x^2 + 10x + 21)
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It'll be (x + a)*(x + b), since there are no minus signs.
These problems always use integers.
So a and b multiply to 21, and add up to 10.
21 can only be 1x21 or 3x7.
Only 3 and 7 add up to 10, so it's
(x + 3)*(x + 7)