Philip P. answered • 06/02/14
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Effective and Patient Math Tutor
Factoring is a big topic - too big to address adequately in this short space. Try looking over this lesson on factoring.
http://www.wyzant.com/resources/lessons/math/algebra/factoring
If you have specific questions, or would like a specific equation factored, post it here and we'll help.
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126x3-54x2-210x+90
Group as follows:
(126x3-54x2) - (210x-90)
You can factor an 18x2 out of the terms in the first parentheses and a 30 out of the terms in the second parentheses:
18x2(7x-3) - 30(7x-3)
Now factor out the (7x-3):
(18x2-30)(7x-3)
Finally, I can factor out a 6 from the terms in the first parentheses:
6(3x2-5)(7x-3)
Check by multiplying out the factored expression (FOIL) to verify that you get the original expression back.
Philip P.
126x3-54x2-210x+90
Let's group the first 2 terms together and the last two together:
(126x3-54x2) - (210x-90)
I can factor out 18x2 out of (126x3-54x2)
(126x3-54x2) = 18x2(7x-3)
I can factor a 30 out of the second two terms:
(210x-90) = 30(7x-3)
Combining:
(126x3-54x2) - (210x-90) = 18x2(7x-3) - 30(7x-3)
Finally, factor the (7x-3) out of the two terms:
18x2(7x-3) - 30(7x-3) = (18x2-30)(7x-3)
Finally, I can factor a 6 out of the (18x2-30) term:
6(3x2-5)(7x-3)
Check by FOILing it to see if you get the original expression.
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06/03/14
Jermaine G.
06/02/14