(0) \( 3 x(x+3) \)

Did you know that the expression \( 3x(x+3) \) represents a quadratic function when expanded? You can easily expand it to get \( 3x^2 + 9x \). This kind of function has a parabolic shape, and its graph can tell us a lot about its roots and vertex, which are key in algebra! In real-world scenarios, such quadratic functions arise in various fields, like physics and economics. For example, if you're calculating the area of a rectangular garden where one side's length is represented by \( x \) and the other by \( x + 3 \), the expression reflects the relationship of dimensions to the total area. Expanding and analyzing would help determine how changes in size could impact planting space!