[tex]f(x)=ax+b~~-szukana~~funkcja~~liniowa\\\\f(0)=-3~~\Rightarrow~~A=(0,-3)~~\Rightarrow~~A\in f(x)\\\\f(1)=-1~~\Rightarrow~~B=(1,-1)~~\Rightarrow~~B\in f(x)\\\\Do~~szukanej~~funkcji~~f(x)~~podstawiam~~punkty~~A~~oraz~~B\\\\\left \{ {{a\cdot 0+b=-3} \atop {a\cdot 1+b=-1}} \right. \\\\\left \{ {{b=-3} \atop {a+b=-1}} \right. \\\\\left \{ {{b=-3} \atop {a-3=-1}} \right.\\\\\left \{ {{b=-3} \atop {a=-1+3}} \right.\\\\\left \{ {{b=-3} \atop {a=2}} \right.\\\\[/tex]
[tex]f(x)=2x-3~~-wzor~~szukanej~~funkcji~~liniowej\\\\sprawdzam~~czy~~punkty~~A~~oraz~~B~~naleza~~do~~f(x)\\\\f(0)=2\cdot 0 -3=-3~~\Rightarrow~~A\in f(x)\\\\f(1)=2\cdot 1 -3=2-3=-1~~\Rightarrow~~B\in f(x)[/tex]
