Решение:
$$3 \cdot 2 = 6$$
$$6 : 2 = 3$$
$$6 : 3 = 2$$
$$4 \cdot 2 = 8$$
$$8 : 2 = 4$$
$$8 : 4 = 2$$
$$5 \cdot 2 = 10$$
$$10 : 2 = 5$$
$$10 : 5 = 2$$
$$6 \cdot 2 = 12$$
$$12 : 2 = 6$$
$$12 : 6 = 2$$
$$7 \cdot 2 = 14$$
$$14 : 2 = 7$$
$$14 : 7 = 2$$
$$8 \cdot 2 = 16$$
$$16 : 2 = 8$$
$$16 : 8 = 2$$
$$9 \cdot 2 = 18$$
$$18 : 2 = 9$$
$$18 : 9 = 2$$