When a piece-wise function is given, that is, a function that has <em>multiple definitions</em>, the numeric value at x when the definition changes is given by the closed circle.
For function L(x), when x = 2, the closed circle is at y = 7, hence, L(2) = 7.
For function R(x), when x = 2, the closed circle is at y = 1, hence, R(2) = 1.