Odpowiedź:
[tex]x^2-(3x-1)^2=56x-43\\\\x^2-(9x^2-6x+1)=56x-43\\\\x^2-9x^2+6x-1-56x+43=0\\\\-8x^2-50x+42=0\ \ /:(-2)\\\\4x^2+25x-21=0\\\\\Delta=b^2-4ac\\\\\Delta=25^2-4*4*(-21)=625+336=961\\\\\sqrt{\Delta}=\sqrt{961}=31\\\\\\x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-25-31}{2*4}=\frac{-56}{8}=-7\\\\\\x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-25+31}{2*4}=\frac{6}{8}=\frac{3}{4}[/tex]
