Question

verify that xy[(x+y) (1/x+1/y)] = (x+y)^2

Answer 1

$xy(1 + \frac{x}{y} + \frac{y}{x} + 1) \\ xy + {x}^{2} + {y }^{2} + xy \\ {x}^{2} + 2xy + {y}^{2} \\ (x + y) {2}$