Do rozwiązania mamy układ równań.
[tex]\left \{ {{y=2x+8} \atop {x+3y-3=0}} \right. \\\\\left \{ {{-2x+y=8} \atop {x+3y=3~~\mid \cdot 2}} \right. \\\\\left \{ {{-2x+y=8} \atop {2x+6y=6}} \right. ~~\mid + ~~dodaje~~stronami\\\\-2x+y+2x+6y=8+6\\\\7y=14~~\mid \div 7\\\\y=2\\\\x+3y-3=0~~\land~~y=2~~\Rightarrow~~x+3\cdot 2 -3=0\\\\x+3\cdot 2 -3=0\\\\x+6-3=0\\\\x+3=0\\\\x=-3\\\\\\Odp:~~\left \{ {{y=2} \atop {x=-3}} \right. \\\\[/tex]
[tex]sprawdzam:\\\\I.~~y=2x+8~~\land~~x=-3~~\land~~y=2\\\\L=2\\\\P=2\cdot (-3) + 8 = -6+8=2\\\\L=P\\\\II.~~x+3y-3=0~~\land~~x=-3~~\land~~y=2\\\\L=-3+3\cdot 2 -3 =-3+6-3=0\\\\P=0\\\\L=P[/tex]
