We can consider a complex number as a point on a plane such that a+ib=(a,b).
Furthermore, the distance between two points on a plane is given by the formula below.
[tex]D=\sqrt[]{(x_1-x_2)^2+(y_1-y_2)^2}[/tex]
Therefore, in our case,
[tex]\begin{gathered} 5=5+i0=(5,0) \\ 4i=0+4i=(0,4) \\ \end{gathered}[/tex]
Then,
[tex]\Rightarrow D=\sqrt[]{(5-0)^2+(0-4)^2}=\sqrt[]{25+16}=\sqrt[]{41}[/tex]
Therefore, the answer is sqrt(41). Type in 41
