Odpowiedź:
[tex]a=-9\ \ ,\ \ b=a+5\ \ ,\ \ c=-4\\\\b^2=a\cdot c\\\\(a+5)^2=-9\cdot(-4)\\\\a^2+10a+25=36\\\\a^2+10a+25-36=0\\\\a^2+10a-11=0\\\\a=1\ \ ,\ \ b=10\ \ ,\ \ c=-11\\\\\Delta=b^2-4ac\\\\\Delta=10^2-4\cdot1\cdot(-11)=100+44=144\\\\\sqrt{\Delta}=\sqrt{144}=12\\\\x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-10-12}{2\cdot1}=\frac{-22}{2}=-11\\\\x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-10+12}{2\cdot1}=\frac{2}{2}=1[/tex]
