Question

Write power sets of the following
$\left\{a\right\}$

Answer 1

$\left\{a\right\}$
Subsets of $\left\{a\right\}$ are $\varphi$ and $\left\{a\right\}$
Hence $P\left\{a\right\}=\left\{\right\{\varphi \},\{a\left\}\right\}$