document.write( "Question 132558: Find all numbers for which the rational expression is undefined.\r
\n" ); document.write( "\n" ); document.write( "I can't remember how to do this.\r
\n" ); document.write( "\n" ); document.write( "m^3 - 4m
\n" ); document.write( "_________\r
\n" ); document.write( "\n" ); document.write( "m^2 - 64\r
\n" ); document.write( "\n" ); document.write( "This is supposed to look like a fraction. I can't figure out how to set it up. Sorry.
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Algebra.Com's Answer #96871 by Earlsdon(6294)\"\" \"About 
You can put this solution on YOUR website!
Find all numbers for which the rational expression is undefined:
\n" ); document.write( "\"%28m%5E3-4m%29%2F%28m%5E2-64%29\"
\n" ); document.write( "Ok, such an expression will be undefined whenever the denominator equals zero.
\n" ); document.write( "So, if you set the denominator (\"m%5E2-64\") equal to zero then solve for the varable m, you will have your answer.
\n" ); document.write( "\"m%5E2-64+=+0\" Add 64 to both sides.
\n" ); document.write( "\"m%5E2+=+64\" Now take the square root of both sides.
\n" ); document.write( "\"m+=+8\" or \"m+=+-8\" These are the numbers that make the expression undefined.
\n" ); document.write( "Check:
\n" ); document.write( "\"%28m%5E3-4m%29%2F%28m%5E2-64%29\" Substitute m = 8
\n" ); document.write( "\"%288%5E3-4%288%29%29%2F%288%5E2-64%29\"
\n" ); document.write( "\"%28512-32%29%2F%2864-64%29\"
\n" ); document.write( "\"480%2F0\" Division by zero is undefined!
\n" ); document.write( "Similarly for m = -8
\n" ); document.write( "\"%28%28-8%29%5E3-4%28-8%29%29%2F%28%28-8%29%5E2+-+64%29\"
\n" ); document.write( "\"%28-512%2B32%29%2F%2864-64%29\"
\n" ); document.write( "\"%28-480%29%2F0\" Division by zero is undefined!
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