Question 1052643
Multiply both sides by {{{6*5=30}}},
{{{6x+5y=840}}}
{{{5x+6y=840}}}
Multiplying eq. 1 by {{{5}}} and eq. 2 by {{{-6}}} and adding,
{{{30x+25y-30x-36y=840(5)-840(6)}}}
{{{-11y=-840}}}
{{{y=840/11}}}
Then,
{{{6x+5(840/11)=840}}}
{{{6x=840(1-5/11)}}}
{{{6x=840(6/11)}}}
{{{x=840/11}}}