This is an inline (a^=x-b^) equation.

This is an inline $a^*=x-b^*$ equation.

These are block equations:

\[a^*=x-b^*\] \[ a^*=x-b^* \] \[ a^*=x-b^* \]

These are block equations using alternate delimiters:

$$a^*=x-b^*$$ $$ a^*=x-b^* $$ $$ a^*=x-b^* $$