# How do you find the conjugate of (7A + 3B - 4i)?

Jan 29, 2016

$\overline{z} = \left(7 A + 3 B\right) \textcolor{red}{+} 4 i$

#### Explanation:

Given:

$z \in \mathbb{C}$

$z = a + i b$

the complex conjugate is

$\overline{z} = a \textcolor{red}{-} i b$

Same real part but opposite immaginary part.

In your case, assuming that $A , B \in \mathbb{R}$

$\therefore \overline{z} = \left(7 A + 3 B\right) \textcolor{red}{+} 4 i$