Решим каждый пример по порядку:
$$4 \times 8 = 32$$
$$24 - 12 = 12$$
$$16 : 2 = 8$$
$$9 : 3 = 3$$
$$32 - 16 = 16$$
$$5 + 4 = 9$$
$$18 + 3 = 21$$
$$21 : 3 = 7$$
$$3 \times 8 = 24$$
$$12 : 4 = 3$$
$$15 : 3 = 5$$
$$7 + 8 = 15$$
Ответ:
$$4 \times 8 = 32$$
$$24 - 12 = 12$$
$$16 : 2 = 8$$
$$9 : 3 = 3$$
$$32 - 16 = 16$$
$$5 + 4 = 9$$
$$18 + 3 = 21$$
$$21 : 3 = 7$$
$$3 \times 8 = 24$$
$$12 : 4 = 3$$
$$15 : 3 = 5$$
$$7 + 8 = 15$$