Each of the values that can be substituted for the variables in an equation to find a true equality. The set of all these values is called the solution set of the equation.

### Example

Consider the equation “2*x* + *y* = 12″ in which the variables *x* and *y* are defined in the set E = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}.

- The pair (5, 2) is a solution to this equation, because “2 × 5 + 2 = 12”.
- Therefore, the solution set of this equation is: {(1, 10), (2, 8), (3, 6), (4, 4), (5, 2), (6, 0)}.