Inline math

$x^2$ and $a$
.
<p><code class="language-math math-inline">x^2</code> and <code class="language-math math-inline">a</code></p>

costs $5 and $10
.
<p>costs $5 and $10</p>

a $, $$b and $a $b$
.
<p>a $, $$b and $a <code class="language-math math-inline">b</code></p>