C1: Gia tri cua \(\frac{3\left(x+y\right)^2}{3\left(x-y\right)^2}\) . Voi xy =\(\frac{1}{2}\)
C2: gia tri cua \(x\left(2x+y\right)+xy+\frac{1}{2}y^2\) . Biet \(8x^3+12x^2y+6xy^2+y^3=27\)
C3 : gia tri cua \(3x^2-12xy+12y^2\) . Biet \(x^3-6x^2y+12xy^2-8x^3=-8\)