Question 694249
y=t when x=-5 so 
{{{ 2(-5)-10t=-6 }}}
{{{ -10-10t=-6 }}}
{{{ -10+6=10t }}}
{{{ 10t=-10+6 }}}
{{{ 10t=-4 }}}
{{{ t=-0.4 }}}

Check: x=-5, y=-0.4 then
{{{ 2x-10y=2(-5)-10(-0.4)=-10+4=-6 }}}