## Elementary Technical Mathematics

$5$
First, rewrite the equation in the form $$5-\frac{7}{x}=\frac{18}{5}.$$ By multiplying both sides by $5x$ and simplifying, we get $$25x-35=18x \Longrightarrow 7x=35.$$ By dividing both sides by $7$, we have $$x= \frac{35}{7}=5.$$