Question 1103886
{{{3H+2F=19}}}
{{{5H+3F=31}}}
Multiply eq. 1 by 3 and eq. 2 by 2 and subtract 1 from 2 to eliminate F.
{{{3(3H+2F)-2(5H+3F)=3(19)-2(31)}}}
{{{9H+6F-10H-6F=57-62}}}
{{{-H=-5}}}
{{{H=5}}}
Now use either equation to solve for F.