Question 387167: can you send me a problems showing the steps on how to show the foil method Found 2 solutions by stanbon, Edwin McCravy:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! show the foil method
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Here's the pattern:
(a+b)(c+d)
F: ac (the F means "first time first"
O: ad (the O means "multiply the outers"
I: bc (the I means "multiply the inners"
L: bd (the L means "last times last"
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Example:
(x + 3)(2x- 5)
F: x*2x = 2x^2
O: x*-5 = -5x
I: 3*2x = 6x
L: 3*-5 = -15
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Combines those to get the answer:
2x^2+x-15
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Cheers,
Stan H.
FOIL (or F.O.I.L.) is an acronym for "FIRSTS, "OUTERS", "INNERS", "LASTS".
When you have two parentheses multiplied with two terms in each,
like this:
(A + B)(C + D)
(A + B)(C + D)
A and the C are the FIRST terms in each parentheses
You multiply them together and in this case you get AC
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(A + B)(C + D)
The A and the D are the OUTER ones in each parentheses (the furthest apart)
You multiply them together and in this case you get AD
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(A + B)(C + D)
The B and the C are the INNER ones in each parentheses (the closest ones together)
You multiply them together and in this case you get BC
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(A + B)(C + D)
The B and the D are the LAST ones in each parentheses
You multiply them together and in this case you get BD
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So the sum of all four of them is F + O + I + L or
AC + AD + BC + BD
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Edwin
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