When creating a model, you have a great deal of flexibility in choosing cells to use, and calculating the objective and constraints. For example, the objective function will ultimately depend on the decision variable cells, but you don’t have to calculate the entire function in one formula cell. You can use any number of formula cells to compute intermediate results, and use these to calculate the objective function or the constraints.
You can write a linear expression easily with Google Sheets' SUMPRODUCT function, or you can use + and * operators, as shown below. You can use Google Sheets' array formulas and functions that return vector and matrix results. And you can use the rich facilities within Google Sheets to access data in external text files, and Web pages to ‘populate’ your model.