The expression "2x + 3" is a simple algebraic equation where "x" represents a variable. The "2x" part indicates that the variable is multiplied by 2, while the "+ 3" means that 3 is added to the result. This expression can be used to represent various relationships in mathematics, such as in linear equations. In a graph, "2x + 3" can be visualized as a straight line. The slope of the line is 2, meaning for every increase of 1 in "x," the value of the expression increases by 2. The "+ 3" indicates that the line crosses the y-axis at the point (0, 3).