The expression "2i + 2" combines a real number and an imaginary number. Here, "2" is a real number, while "2i" represents an imaginary number, where "i" is the imaginary unit defined as the square root of -1. This expression can be seen as a point in the complex plane, where the x-axis represents real numbers and the y-axis represents imaginary numbers. In the context of complex numbers, "2i + 2" can be rewritten as "2 + 2i." This format highlights the real part (2) and the imaginary part (2i) separately. Complex numbers, such as this expression, are essential in various fields, including mathematics, engineering, and physics, for solving equations that involve square roots of negative numbers.