Question 1197326


{{{(3/7)+(7/12)=(1/N)}}}


{{{(3*12)/(7*12)+(7*7)/(12*7)=(1/N)}}}

{{{36/84+49/84=(1/N)}}}

{{{85/84=(1/N)}}}................cross multiply

{{{85N=1*84}}}

{{{N=84/85}}}