document.write( "Question 25485: why must you reverse the inequality sign when multiplying or dividing both sides by a negative number? \n" ); document.write( "
Algebra.Com's Answer #13778 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Consider the arithmetic of this statement:
\n" ); document.write( " 2<7
\n" ); document.write( "Now multiply both sides by (-1)
\n" ); document.write( "If you did not switch the inequality sign you
\n" ); document.write( "would get -2<-7
\n" ); document.write( "But that is not true:
\n" ); document.write( "You must switch the inequality sign to get -2>-7\r
\n" ); document.write( "\n" ); document.write( "Or consider 2<-3y
\n" ); document.write( "Let's say you want to solve for \"y\"
\n" ); document.write( "Add 3y to both sides to get 3y+2<0
\n" ); document.write( "Now subtract \"2\" from both sides to get
\n" ); document.write( "3y<-2
\n" ); document.write( "You started with 2<-3y
\n" ); document.write( "and ended with 3y<-2
\n" ); document.write( "See how the inequality has switched.\r
\n" ); document.write( "\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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