Решение:

a) $$72 \cdot 50 + 50 \cdot 28 + 14^2 = $$

1. $$72 \cdot 50 = 3600$$
2. $$50 \cdot 28 = 1400$$
3. $$14^2 = 14 \cdot 14 = 196$$
4. $$3600 + 1400 + 196 = 5196$$

Ответ: $$5196$$

б) $$675 \cdot 1 + 9 \cdot 675 - 5^3 : (5^2 - 3845 \cdot 0) = $$

1. $$675 \cdot 1 = 675$$
2. $$9 \cdot 675 = 6075$$
3. $$5^3 = 5 \cdot 5 \cdot 5 = 125$$
4. $$5^2 = 5 \cdot 5 = 25$$
5. $$3845 \cdot 0 = 0$$
6. $$25 - 0 = 25$$
7. $$125 : 25 = 5$$
8. $$675 + 6075 - 5 = 6745$$

Ответ: $$6745$$