In the given figure; the area of unshaded portion is 75% of the area of the shaded portion. Find the value of x.

Find the compounded ratio of :

(i) (a - b) : (a + b) and (b² + ab) : (a² - ab)

(ii) (x + y) : (x - y), (x² + y²) : (x + y)² and (x² - y²)² : (x⁴ - y⁴)

(iii) (x² - 25) : (x² + 3x - 10); (x² - 4) : (x² + 3x + 2) and (x + 1) : (x² + 2x).