If $$(56\sqrt{7}x^3-2\sqrt{2}y^3)\div(2\sqrt{7}x-\sqrt{2}y)=Ax^2+By^2-Cxy$$, then find the value of $$A + B - \sqrt{14}C$$.

$$(56\sqrt{7}x^3-2\sqrt{2}y^3)\div(2\sqrt{7}x-\sqrt{2}y)=Ax^2+By^2-Cxy$$

$$\frac{\left(2\sqrt{7}x-\sqrt{2}y\right)\left(28x^2+2\sqrt{14}xy+2y^2\right)}{\left(2\sqrt{7}x-\sqrt{2}y\right)}=Ax^2+By^2-Cxy$$

$$28x^2+2\sqrt{14}xy+2y^2=Ax^2+By^2-Cxy$$

Comparing both sides,

A = 28, B = 2, C = $$-2\sqrt{14}$$

$$A+B-\sqrt{14}C=28+2-\sqrt{14}\left(-2\sqrt{14}\right)$$

$$=30+28$$

$$=58$$

Hence, the correct answer is Option D