I've managed to simplify $\bar{a}\bar{b}(\bar{a} + b)(\bar{b} + b)$ to $\bar{a} +\bar{a}\bar{b}$
Where $\bar{a}$ = $a$ complement I simplified the original expression with Huntingtons Postulates, Idempotent laws etc
I've checked they are equivalent by truth table. Can this be simplified even further?