If 2x - 3y = 10 and xy = 16, find the value of 8x³ - 27y³.

Expand (3x + 5y + 2z)(3x - 5y + 2z)

The sum of two numbers is 9 and their product is 20. Find the sum of their :

(i) squares

(ii) cubes.

Two positive numbers x and y are such that x > y. If the difference of these numbers is 5 and their product is 24, find :

(i) sum of these numbers.

(ii) difference of their cubes.

(iii) sum of their cubes.