What is an imaginary number?

An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by it's property i² = −1. The square of an imaginary number bi is −b². For example, 5i is an imaginary number, and it's square is −25.

i = 2 / - 5

step-by-step explanation:

evaluation of ( 2 - 4 ) ( p + q ) when p = 2 and q = 5 i, by putting values of p and q,