(a) \( \frac{1}{a b}+\frac{2}{b c}+\frac{3}{a c} \)

This expression can be simplified or evaluated by finding a common denominator, which is \(abc\). When we rewrite each term using this common denominator, we have: \[ \frac{c}{abc} + \frac{2a}{abc} + \frac{3b}{abc} = \frac{c + 2a + 3b}{abc} \] You can plug in specific values of \(a\), \(b\), and \(c\) to get a numerical result, or use it in a larger equation if needed! Alternatively, if you're dealing with this in problem scenarios or calculus, consider applying it in systems of equations or optimization problems where minimizing or maximizing values of \(a\), \(b\), and \(c\) could lead to interesting real-world solutions, such as maximizing resources in production.