How do I specify 8^(a - b) in math mode

Question

$8^(a - b)$ produces only a superscripted (; the rest of the power is not superscripted.

How can I superscript the whole (a-b) portion?

Answer 1

Put braces around the entire part that you want superscripted:

$8^{(a - b)}$

Answer 2

To always get it right you can define a command probably like

  \newcommand{\mpower}[2]{\ensuremath{#1^{#2}}}

For example:

  \mpower{8}{(a-b)}