Zadanie 2 :
[tex]y=x^2+2x-15\\\\a=1, \ b=2, \ c=-15\\\\\Delta=b^2-4ac\rightarrow2^2-4\cdot1\cdot(-15)=4+60=64\\\\p=\frac{-b}{2a}\rightarrow\frac{-2}{2\cdot1}=-\frac{2}{2}=-1\\\\q=\frac{-\Delta}{4a}\rightarrow\frac{-64}{4\cdot1}=\frac{-64}{4}=-16\\\\y=a(x-p)^2+q\\\\\boxed{y=(x+1)^2-16}[/tex]
Zadanie 3 :
[tex]y=2(x+4)(x-5)\\\\y=2(x^2-5x+4x-20)\\\\y=2x^2-10x+8x-40\\\\\boxed{y=2x^2-2x-40}[/tex]
Zadanie 4 :
[tex]y=3(x-2)^2+5\\\\y=3(x^2-4x+4)+5\\\\y=3x^2-12x+12+5\\\\\boxed{y=3x^2-12x+17}[/tex]
