Question

(2x-3)(x+1)=x^2+17 еще одно)

Answer 1

 (2x-3)(x+1)=x²+17
2x²-3x+2x-3=x²+17
2x²-x²-3x+2x-3-17=0
x²-x-20=0
D=1²-4*1*(-20)=1+80=81=9²
$x_{1}= frac{-(-1)- sqrt{81} }{2*1} = frac{1-9}{2} = frac{-8}{2} =-4 \ x_{2}= frac{-(-1)+ sqrt{81} }{2*1} = frac{1+9}{2} = frac{10}{2} =5$

Answer 2

2x^2+2-3x-3=x^2+17
2x^2-x^2-3x+2-3-17=0
x^2-3x-18=0

D=b^2-4ac=(-3)^2-4 *(-18)=9+72=81^2=9

x1=-b-D/2a=3-9/2=-3
x2=-b+D/2a=3+9/2=6