Question Video: Deciding Whether a Given Number Is Real- Imaginary- or Complex Mathematics • First Year of Secondary School

Video Transcript

What type of number is negative three plus five 𝑖? Is it (A) real, (B) purely imaginary, or (C) complex?

The number negative three plus five 𝑖 is made up of two parts: a real part, negative three, and an imaginary part, five 𝑖. We recall that any number written in the form 𝑎 plus 𝑏𝑖 is a complex number. 𝑎 and 𝑏 must be nonzero real values and in this case are equal to negative three and five. The correct answer is option (C). The number negative three plus five 𝑖 is a complex number.