a) $$(24 * 258 : 43 + 4590 : 102 - 20) : 13$$
1. $$24 * 258 = 6192$$
2. $$6192 : 43 = 144$$
3. $$4590 : 102 = 45$$
4. $$144 + 45 = 189$$
5. $$189 - 20 = 169$$
6. $$169 : 13 = 13$$
Ответ: 13
б) $$(372 + 118 * 6) : (38 * 35 - 34 * 37) - 12$$
1. $$118 * 6 = 708$$
2. $$372 + 708 = 1080$$
3. $$38 * 35 = 1330$$
4. $$34 * 37 = 1258$$
5. $$1330 - 1258 = 72$$
6. $$1080 : 72 = 15$$
7. $$15 - 12 = 3$$
Ответ: 3