[tex]a) \\\\k:-x+5y-7=0\\5y=x+7 /:5\\y=\frac{x+7}5\\y=\frac15x+\frac75\\\\a_1=\frac15\\\\\frac15*a_2=-1 /*5\\a_2=-5\\\\11=-5*(-3)+b\\11=15+b /-15\\-4=b\\\\y=-5x-4[/tex]
[tex]b) \\\\\left \{ {{9=-3a+b} \atop {12=-3a+b}} \right. \\\\\\x=-3\\\\\text{Te punkty naleza do jednej prostej o rownaniu x=-3}[/tex]
