First;
5-8÷4x2-1, put parenthesis around the multiplication like so; 5-8÷(4x2)-1
Solve the problem in the parenthesis; 4x2=8 so; 5-8÷(8)-1
Then put parenthesis around the division; 5-(8÷(8))-1
Solve the problem within the parenthesis; (8÷(8))=1
The problem should look like this now 5-1-1
Now subtract; 5-1=4-1=3
Your answer is 3.
Let me know if I did this wrong or if you have any questions. (: