(x-2)^2-2(x-1)^2=(3-х)(3+х)
x^2-4x+4-(2x+1)^2=9+3x-3x-x^2
x^2-4x+4-(4x^2+4x+1)=9+3x-3x-x^2
x^2-4x+4-4x^2-4x-1=9+3x-3x-x^2
x^2-4x^2+x^2-4x-4x-3x+3x=-4+1+9
-2x^2-8x-6=0
2x^2+8x+6=0
D=64-48=4^2
x1=-8+4/4=-1
x2=-8-4/4=-3
(x-2)^2-2(x-1)^2=(3-х)(3+х)
x^2-4x+4-(2x+1)^2=9+3x-3x-x^2
x^2-4x+4-(4x^2+4x+1)=9+3x-3x-x^2
x^2-4x+4-4x^2-4x-1=9+3x-3x-x^2
x^2-4x^2+x^2-4x-4x-3x+3x=-4+1+9
-2x^2-8x-6=0
2x^2+8x+6=0
D=64-48=4^2
x1=-8+4/4=-1
x2=-8-4/4=-3