How to standardize the operation research

How to standardize the operation research

1. For the minimum of objective function, the opposite number is used to replace the transformation to get the maximum;
2. If the constraint condition is > = plus a positive residual variable, if it is = 0, if it is less than or equal to, then use the opposite number, if the sign is uncertain, then it is expressed as the subtraction of two positive variables;

In the plane rectangular coordinate system, the set C = {(x, y) y = x} represents the straight line y = X. from this angle, what does the set D = {(x, y) 2x − y = 1x + 4Y = 5} represent? What is the relationship between sets C and D?

The set D represents the intersection of the line 2x-y = 1 and the line x + 4Y = 5. By solving the equations 2x − y = 1x + 4Y = 5, we get x = 1, y = 1; that is, d = {(1,1)}, obviously (1,1) on the line y = x, ■ (1,1) ∈ C, ■ D ⊆ C

A set of all points on the x-axis in a rectangular plane coordinate system

There are (x, 0), X is any natural number
Sorry, specific mathematical symbols, I can't type out, you translate it yourself~

A set of all points on the x-axis in a rectangular plane coordinate system
Set represented by enumeration: {x ∣ (x-4) (x + 2) = 0, X belongs to Z}
Set represented by enumeration: {x ∣ - 1

{(x, y) | y = 0, X belongs to R}