Complex Numbers

Find the real and imaginary parts of the complex number $\dfrac{2 + 5i}{4 - 3i}$


The given complex number is

$\begin{aligned} z & = \dfrac{2 + 5i}{4 - 3i} \\\\ & = \left(\dfrac{2 + 5i}{4 - 3i}\right) \times \left(\dfrac{4 + 3i}{4 + 3i}\right) \\\\ & = \dfrac{8 + 26 i + 15 i^2}{16 - 9 i^2} \\\\ & = \dfrac{-7 + 26 i}{25} \;\;\; \left[\because i^2 = -1\right] \\\\ & = \dfrac{-7}{25} + \dfrac{26i}{25} \end{aligned}$

$\therefore$ $\;$ Real part $= \dfrac{-7}{25}$; $\;\;$ Imaginary part $= \dfrac{26}{25}$