document.write( "Question 241503: I need help with solving this equation.Find all numbers for which the rational expression is undefined \r
\n" ); document.write( "\n" ); document.write( "n^3-7n/n^2-4 (this problem is division) \n" ); document.write( "

Algebra.Com's Answer #176894 by College Student(505) $\"\"$ $\"About$

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In order for a fraction to be undefine, its denominator would equal to zero. So, let the denominator (by itself) equal to zero and find the solution(s).
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\n" ); document.write( " $\"n%5E2-4=0\"$
\n" ); document.write( " $\"n%5E2=4\"$
\n" ); document.write( "Take the square root on both sides of the equation to determine the value of n.
\n" ); document.write( " $\"sqrt%28n%5E2%29=sqrt%284%29\"$
\n" ); document.write( "Since the square root of a number raised to the 2nd power cancel each other, we can re-write the equation like this:
\n" ); document.write( " $\"n=sqrt%284%29\"$
\n" ); document.write( "This will yield two possible answers:
\n" ); document.write( "n=2 and n=-2
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\n" ); document.write( "Check:
\n" ); document.write( " $\"2%5E2=2%2A2=4\"$
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\n" ); document.write( " $\"-2%5E2=-2%2A%28-2%29=4\"$ \n" ); document.write( "

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