Connecting Arithmetic to Algebra  
Multiplication and Binomials

Here it Is !
Rule for Multiplication of binomals

(X + Y) * (X + Y)

• First digit from the first factor times the first digit of the second factor
  (First - F)
• First digit from the first factor times the second digit of the second factor
  (Outside - O)
• Second digit from the first factor times the first digit of the second factor
• (Inside - I)
• Second digit from the first factor times the second digit of the second factor
  (Last - L)

First factor				x	+	y
Second factor				x	+	y

First digit from the first factor times the first digit of the second factor (F)		x	*	x	=	x2
First digit from the first factor times the second digit of the second factor (O)		x	*	y	=	xy
Second digit from the first factor times the first digit of the second factor (I)		x	*	y	=	xy
Second digit from the first factor times the second digit of the second factor (L)		y	*	y	=	y2
		x2	+	2xy	+	y2

 

 

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Dr. Robert Sweetland's notes