Zadanie 2
(2x-1)^2-(3x-5)^2=(x+1)(5-x)+1
4x^2-4x+1-(9x^2-30x+25)=5x-x^2+5-x+1
4x^2-4x+1-9x^2+30x-25=4x-x^2+6
4x^2-4x+1-9x^2+30x-25-4x+x^2-6=0
-4x^2+22x-30=0 |:2
-2x^2+11x-15=0
a=-2, b=11, c=-15
\Delta=b^2-4ac=121-4*(-2)*(-15)=121-120=1
\sqrt\Delta=1
x_1=\frac{-b-\sqrt\Delta}{2a}=\frac{-11-1}{2*(-2)}=\frac{-12}{-4}=3
x_2=\frac{-b+\sqrt\Delta}{2a}=\frac{-11+1}{-4}=\frac{-10}{-4}=\frac{5}{2}=2,5