5x+y=9 /-5x
2x+3y=1
y=9-5x
2x+3y=1
y=9-5x
2x+3*(9-5x)=1
y=9-5x
2x+27-15x=1
y=9-5x
-13x+27=1 /-27
y=9-5x
-13x=-26 /:(-13)
y=9-5x
x=2
y=9-5*2
x=2
y=9-10
x=2
y=-1
x=2
x=2
y=-1
5x+y=9 /-5x
2x+3y=1
y=9-5x
2x+3y=1
y=9-5x
2x+3*(9-5x)=1
y=9-5x
2x+27-15x=1
y=9-5x
-13x+27=1 /-27
y=9-5x
-13x=-26 /:(-13)
y=9-5x
x=2
y=9-5*2
x=2
y=9-10
x=2
y=-1
x=2
x=2
y=-1
{5x+y=9
{2x+3y=1
{y= 9-5x
{2x+3(9-5x)=1
{y=9-5x
{2x+27-15x=1
{y=9-5x
{-13x= -26
{y= 9-5x
{x= 2
{y= 9-5*2
{x=2
{y= -1
{x=2