Question 1130878
{{{1/91+1/x=1/42}}}

-

LCD, {{{13*6*7*x}}}

{{{(13*7*6x)(1/91+1/x)=(13*7*6x)/(7*6)}}}

{{{6x+91*6=13x}}}

{{{7x=91*6}}}

{{{x=13*6}}}

{{{highlight(x=78)}}}