Tree Representation:

a) A - B /  ( C * D $ E )

0       -
1   A        /	
2        B	    *
3             C        $
4                   D       E

Preorder = -A/B*C$DE
Postorder = ABCDE$*/-

b) A B + C * D E - - F G + $ 

0                    $
1              -           +
2          *         -   F  G   
3       +    C   D  E
4     A  B

Inorder = A+B*C-D-E$F+G
PreOrder = $-*+ABC-DE+FG