28 � 7
4
?33 � 3
?11
42 � ?6
?7
?81 � (?9)
9
12 � 4
3
72 � (?9)
?8
15 � 15
1
?30 � 5
?6
?40 � (?8)
5
56 � (?7)
?8
?21 � (?3)
7
?64 � 8
?8
?8 � 8
?1
?22 � (?2)
11
32 � (?8)
?4
?54 � (?9)
6
60 � (?6)
?10
63 � 9
7
?45 � (?9)
5
?60 � 5
?12
24 � (?3)
?8
?12/6
?2
40/?10
?4
?45/?9
5
a = 4, b =?9, c = ?6
?48 � a
?12
a = 4, b = ?9, c = ?6
b � 3
?3
a = 4, b =?9, c = ?6
9c � b
6
a = 4, b =?9, c = ?6
(ab)/c
6
a = 4, b =?9, c = ?6
(bc)/?6
?9
a = 4, b =?9, c = ?6
(3c)/b
2
a = 4, b =?9, c = ?6
(12a)/c
?8
a = 4, b =?9, c = ?6
(?4b)/4
9
a = 4, b =?9, c = ?6
(ac)/6
?4