Boolen alegbra simplification problem

[Sadeq]

Homework Statement

The problem with right solution is in file 1

The Attempt at a Solution

My attempt is in file 2

iM REALY DONT KNOW WHY THERE IS DIFFERENCE
Please help me to find the mistake

 

[haruspex]

I don't see how you get the third line in your working. Please write out the steps from the second line in more detail.

 

[NattyBumppo]

Your writing is very difficult to read, but I'm trying to help. Are you sure that 2.pdf is your attempt and the attached thumbnail is the correct solution? In fact... would you mind stating the original problem logical expression, as it's not entirely clear?