A) 2(x-3y)^2- 3(x-2y)+12xy dla x=3 i y=-1
2(x^2-6xy+9y^2)-3x+6y+12xy=2x^2-12xy+18y^2-3x+6y+12xy=
2x^2+18y^2-3x+6y=2*3^2+18*(-1)^2-3*3+6*(-1)=18+18-9-6=21
b)
(2x-3y)^2 - x (4x+3y)-9y^2= dla x=\sqrt5- 3 i y= \sqrt5 +3
4x^2-12xy+9y^2=4*(\sqrt5-3)^2-12(\sqrt5-3)(\sqrt5+3)+9(\sqrt5+3)=
4(5-6\sqrt5+9)-(12\sqrt5+36)(\sqrt5+3)+9\sqrt5+27=
20-24\sqrt5-(60+36\sqrt5+36\sqrt5+108)+9\sqrt5+27=
20-24\sqrt5-60-36\sqrt5-108+9\sqrt5+27=