document.write( "Question 131558: (a^negative 1 - b^ negative 1)^ negative 1
\n" ); document.write( "I keep doing this, and getting a-b.
\n" ); document.write( "I have the answer (its in the back of the book) ab/b-a , but I don't know how they got it. \n" ); document.write( "

Algebra.Com's Answer #96035 by solver91311(24713) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"x%5E%28-1%29=1%2Fx\"$ for all real numbers x, $\"x%3C%3E0\"$ .\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So, $\"%28a%5E%28-1%29-b%5E%28-1%29%29%5E-1=1%2F%281%2Fa-1%2Fb%29\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "In order to add the two fractions in the denominator, you need a lowest common denominator. Without any factors in common that we know about, the best we can do for a common denominator is $\"ab\"$ , so:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Note that the original expression is undefined if either $\"a=0\"$ , $\"b=0\"$ , OR $\"a=b\"$ , but the only restriction on the final expression is that $\"a%3C%3Eb\"$ \n" ); document.write( "

\n" );