How can i apply Absorption law in this expression?

Question

I have this expression:

A + A * B * C'

I know that i can use the Absorption law in this and the answer is A, but how can i apply that?

Thank you.

Answer 1

You have to write it as :

$A + (A * (B * C'))$.

Now you can apply Absorption Law.

Answer 2

Absorption Law: A + AB = A in your example let D = BC' A + AD = A

This works because no matter what A is multiplied by, the result of the expression will always be A. This is because if what A is ANDed with is 0 then the result is 0 OR A which is A. However if what A is ANDed with is a 1 then your get A Or A which is again A.