Chapter 1, Problem 8P

Define the variables x and y as x = 5.1 and y = 4.2, then evaluate:

$\text{(a)}\frac{3}{4}xy-\frac{7x}{y^2}+\sqrt{xy}\text{(b)}{\left(xy\right)}^2-\frac{x+y}{\left(x-y\right){|}^2}+\sqrt{\frac{x+y}{2x-y}}$