
Mark H. answered 05/08/19
Tutoring in Math and Science at all levels
Complex numbers are normally graphed on the "complex plane"---the horizontal axis is the real part, and the vertical axis is the imaginary.
Adding and subtracting complex numbers is done with the same method to add and subtract vectors. With complex numbers we already have the linear components, so we simply combine them:
To get z2 - z1:
(4 + i) - (2 - 3i) = (4 - 2) + (i - (-3i)) = 2 + 4i
Plot this on graph paper to make sure it looks right....