Question 1087825
{{{1/(m+5)+1/m=1/6}}}


{{{6m+6(m+5)=m(m+5)}}}
{{{6m+6m+30=m^2+5m}}}
{{{12m+30=m^2+5m}}}
{{{m^2-7m-30=0}}}
{{{(m-10)(m+3)=0}}}
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{{{highlight(m=10)}}}------time for Mark working alone, hours.