Question 274729
{{{x+6y=1}}} {{{x=1-6y}}}
{{{3x-10y=31}}}
______________
{{{3(1-6y)-10y=31}}}
{{{(3-18y)-10y=31}}}
{{{3-28y=31}}}
{{{-28y=28}}}
{{{y=highlight(-1)}}}
{{{x=1-6y}}}
{{{x=1-6(-1)}}}
{{{x=1+6}}}
{{{x=highlight(7)}}}