Can you explain the F.O.I.L method to me
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The FOIL method is used to multiply two binomials. FOIL stands for First, Outer, Inner, Last
If the product (a + b)(c + d) has to be determined, using FOIL:
First : a*c
Adding a*c, a*d, b*c and b*d the product is (a + b)(c + d) = a*c + a*d + b*c + b*d
FOIL stands for first, outer, inner, and last.
It's a way to organize finding the product of
(a + b) (c+d)
The first is ac. The outer is ad. The inner is bc. The last is bd.
So, (a + b) (c+d) = ac + ad + bc +bd.
Often the outer and inner terms are like terms, and the product has three terms instead of four.
Let me show you an example of foil method
(a + b ) (c + d) = ac + ad + bc + bd
(x + 2) (x + 5) = (x)(x) + (5)(x) + (2)(x) + (5)(2)
= x^2 + 5x + 2x + 10 -------> combine like terms
= x^2 + 7x + 10
(X + 5) (2X-3) = (X)(2X) + (X)(-3) + (5)(2X) + (5)(-3)
= 2X^2 + (-3X) + (10X) + (-15) --> Notice the sign
= 2x^2 -3x + 10x -15 -->combine like terms
= 2x^2 +7x -15
(2x - 2)(5x - 2) = (2X)(X) + (2X)(-2) + (-2)(5X) + (-2)(-2)
= 2X^2 + (-4X) + (-10X) + (4)
= 2X^2 -4X - 10X + 4
2X^2 - 14X + 4
hope this helps :)
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