(1)
+A(B-C)
A+(B-C)
(2)
+*A(B-C)*D(F+G)
+(A*(B-C))(D*(F+G))
(A*(B-C))+(D*(F+G))
A*(B-C)+D*(F+G)
(3)
(A+B)(C-D)*(E*F)+
((A+B)*(C-D))(E*F)+
((A+B)*(C-D))+(E*F)
(A+B)*(C-D)+E*F
(4)
ABC(D-E)+**(E*F)-
AB(C+(D-E))**(E*F)-
A(B*(C+(D-E)))*(E*F)-
(A*(B*(C+(D-E))))-(E*F)...