1.
{2x-y=10
{x+5y=-1
{x=-5y-1
{-10y-2-y=10
{x=-5y-1
{-11y=12
{y=-12/11
{x=-5(-12/11)-1
{y=-12/11
{x=60/11-1
{y=-12/11
{x=49/11
{y≈-1,(09)
{x≈4,(45)
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2.
{3m+n=9
{2m-5n=-11
{n=-3m+9
{2m+15m-45=-11
{n=-3m+9
{17m=34
{m=2
{n=-6+9
{m=2
{n=3