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June 26th, 2011, 11:29 PM  #1 
Newbie Joined: Jun 2011 Posts: 20 Thanks: 0  why the product of two negative integers is positive
because the multiplication operation is a repeated addition operation for example (3) x (2) =  ( 3 x 2 ) =  ( (2) + (2) + (2) ) =  ( 6 ) = 6 and 6 is positive integer to view all topics visit my blogger http://imaginemath.blogspot.com/ 
June 26th, 2011, 11:34 PM  #2 
Senior Member Joined: Apr 2007 Posts: 2,140 Thanks: 0 
Let a be positive and b be negative. ab < 0 is correct. Since a is negative, multiplying both sides of the inequality by 1 gives ab > 0.

June 26th, 2011, 11:49 PM  #3 
Newbie Joined: Jun 2011 Posts: 20 Thanks: 0  Re: why the product of two negative integers is positive yes johnny

June 27th, 2011, 02:23 AM  #4 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 521 Math Focus: Calculus/ODEs  Re: why the product of two negative integers is positive
1 = (1)(1) 1 = (1)(1) + 0 1 = (1)(1) + 0(1) 1 = (1)(1) + (1  1)(1) 1 = (1)(1) + (1)(1) + (1)(1) 1 = (1)(1  1) + (1)(1) 1 = (1)(0) + (1)(1) 1 = (1)(1) 
June 27th, 2011, 02:46 AM  #5 
Senior Member Joined: Sep 2010 Posts: 101 Thanks: 0  Re: why the product of two negative integers is positive
then by your assumption: (3)*2=6 (3)*(2)=6 2=2 ??? 
June 27th, 2011, 11:02 AM  #6 
Newbie Joined: Jun 2011 Posts: 6 Thanks: 0  Re: why the product of two negative integers is positive
We can carry out the experiment. Take a piece of paper  it will be our first plane. Draw a line from north to south, this we will create two planeswestern and eastern ( and +).All with the sign () is the property of western plane , sign (+) means that all it belong to east plane. Now draw the same squares in each plane and find their area. If you use negative values ??of length and width in the western plane you get ONLY plus value areas but this is wrong (in our case)!!! Why is this not correct? Because the plus value of the area, are the property east of the plane. One value of length or width should be () and one (+) in western plane. My thoughts ... 
June 27th, 2011, 02:45 PM  #7 
Newbie Joined: Jun 2011 Posts: 20 Thanks: 0  Re: why the product of two negative integers is positive
it is really wonderful job

June 28th, 2011, 05:22 PM  #8  
Global Moderator Joined: Dec 2006 Posts: 20,919 Thanks: 2203  Quote:
 

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