Boolean expression help

Question

I need to simplify the following, although can't find good examples to indicate how to achieve this.

$$(A+\bar{B}).\bar{A}$$

Answer 1

\begin{align}(A + \bar{B}).\bar{A} &= A.\bar{A} + \bar{B}.\bar{A} \\& = False + \bar{B}.\bar{A} \\&= \bar{B}.\bar{A} \\&=\overline{(B+A)}\end{align}

Answer 2

Sit and learn:

http://www.electronics-tutorials.ws/boolean/bool_6.html

This is a simple to learn.

Moreover, I will advice to learn Karnaugh map for harder question.