Question 1208434
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{{{1/f = (n-1)( 1/a + 1/b ) }}}


{{{1/f = (n-1)( b/(ab) + a/(ab) ) }}}


{{{1/f = (n-1)(b+a)/(ab)}}}


{{{ab = f*(n-1)(b+a)}}}


{{{(ab)/((n-1)(b+a)) = f}}}


{{{f = (ab)/((n-1)(b+a))}}}
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