TeX source:

\sum_{i=1}^{n} \sum_{j=1}^{m} C_{i j} X_{i j}+\sum_{j=1}^{m} H_{j} \sum_{i=1}^{n} X_{i}+\sum_{i=1}^{n} \sum_{j=1}^{m} C_{O i j} X_{i j}