If x + 2y - 3 = 0, then find the value of x³ + 8y³ + 6x²y + 12xy² - 125.

If a + b + c = 0, then find the value of $\dfrac{a^2}{bc} + \dfrac{b^2}{ca} + \dfrac{c^2}{ab}$.

Without actually calculating the cubes, find the values of:

(i) (27)³ + (-17)³ + (-10)³

(ii) (-28)³ + (15)³ + (13)³

Using suitable identity, find the value of :

$\dfrac{86 \times 86 \times 86 + 14 \times 14 \times 14}{86 \times 86 - 86 \times 14 + 14 \times 14}$