[tex]\left \{ {{x+3y=13} \atop {4x-y=11}} \right. => \left \{ {{x= 13-3y} \atop {4x-y=11}} \right. \\=> 4x-y= 11\\=> 4*(13-3y) -y=11\\=> 52-12 y-y=11\\=> -13y=-41 => y=\frac{41}{13} \\=> x=13-3y=13-3*\frac{41}{13} = \frac{169-123}{13} = \frac{46}{13}[/tex]
