Gregory saw that the answer to a problem in his friend's textbook was 4+2i. This is an example of which type of number?

an integer

a rational number

a complex number

an irrational number

A complex number.

Complex number is:

a+bi

For this case the first thing you should know is that a complex number is written as follows:

a + bi

Where,

a: real part

bi: imaginary part

We note that for this case:

a = 4

b = 2

Obtaining the following complex number:

4 + 2i

Answer:

This is an example of:

a complex number