#### Answer

$= \frac{5y + 7x - 1}{xy}$

#### Work Step by Step

1) Multiply a fraction with the other denominator to obtain a common denominator between the three fractions. In this case, we multiply the first fraction by $y/y$, the second fraction by $x/x$, and the third fraction we simply leave alone as we already have a common denominator of $xy$
2) Add and then subtract
$= \frac{5}{x} + \frac{7}{y} - \frac{1}{xy}$
$= \frac{5y}{xy} + \frac{7x}{xy} - \frac{1}{xy}$
$= \frac{5y + 7x - 1}{xy}$