Thus, a Linear Programming Problem is one that is concerned with finding the
optimal value (maximum or minimum value) of  a linear function (called objective
function) of several variables (say x and y), subject to the conditions that the variables
are non-negative and satisfy a set of linear inequalities (called linear constraints) The term linear implies that all the mathematical relations used in the problem are
linear relations while the term programming refers to the method of determining a
particular programme or plan of action Before we proceed further, we now formally define some terms (which have been
used above) which we shall be using in the linear programming problems:
Objective function Linear function Z = ax + by, where a, b are constants, which has
to be maximised or minimized is called a linear objective function In the above example, Z = 250x + 75y is a linear objective function