Odpowiedź:
[tex]P=(0,-2)\ \ ,\ \ R=(3,-6)\\\\y=ax+b\ \ - wz\'or\ \ funkcji\ \ liniowej\\\\\begin{cases}-2=a\cdot0+b\\-6=3a+b\end{cases}\\\\\\\begin{cases}-2=0+b\\-6=3a+b\end{cases}\\\\\\\begin{cases}-2=b\\-6=3a+b\end{cases}\\\\\\\begin{cases}b=-2\\-6=3a+b\end{cases}\\\\\\-6=3a+(-2)\\\\-6=3a-2\\\\-6+2=3a\\\\-4=3a\\\\3a=-4\ \ |:3\\\\a=-\frac{4}{3}\\\\\\Szukana\ \ funkcja\ \ ma\ \ wz\'or\\\\y=-\frac{4}{3}x+(-2)\\\\y=-\frac{4}{3}x-2[/tex]
