In a maximization or minimization problem, the objective function represents the quantity being optimized (maximized or minimized). The coefficients of the variables in the objective function determine the direction of the optimization.
A negative coefficient value in the objective function indicates that an increase in the value of the corresponding variable (x) leads to a decrease in the value of the objective function (z).
The common ratio of a geometric sequence cannot be zero because if it were, the sequence would become a series of zeros, which is not considered a geometric sequence.