Question 379725
Multiply numerator and denominator by {{{a^2b^2}}},
{{{(1/a^2+1/b^2)/(1/a+1/b) =(b^2+a^2)/(b^2a+a^2b)}}}
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{{{(1/a^2+1/b^2)/(1/a+1/b) =highlight((a^2+b^2)/(ab(a+b)))}}}