I. $frac{{15}}{{sqrt x }} - frac{2}{{sqrt x }} = 6sqrt x$

II. $frac{{sqrt y }}{4} + frac{{7sqrt y }}{{12}} = frac{1}{{sqrt y }}$

(i) $frac{{15}}{{sqrt x }} - frac{2}{{sqrt x }} = 6sqrt x$

15 – 2 = 6x

$x = frac{{13}}{6}$

(ii) $frac{{sqrt y }}{4} + frac{{7sqrt y }}{{12}} = frac{1}{{sqrt y }}$

$frac{{3sqrt y + 7sqrt y }}{{12}} = frac{1}{{sqrt y }}$

$10y = 12$

$y = frac{{12}}{{10}} = frac{6}{5}$

Hence x > y