Hai số phức $z = a + bi,z' = a + b'i$ bằng nhau nếu:

$a$

$b$

$i$

$z$

$- 1$

$2$

$1$

$\sqrt 2$

$a - bi$          

$a + bi$ 

$b - ai$          

$b + ai$

$\overline z  = z$       

$\left| {\overline z } \right| = \left| z \right|$             

$\left| z \right| + \left| {\overline z } \right| = 0$

$\left| {\overline z .z} \right| = 0$

$M\left( {a;a'} \right)$

$N\left( {b;b'} \right)$          

$M\left( {a;b} \right)$

$N\left( {b';a'} \right)$ 

$z + z' = \left( {a + b} \right) + \left( {a' + b'} \right)i$        

$z - z' = \left( {a + a'} \right) - \left( {b + b'} \right)i$ 

$z.z' = \left( {aa' - bb'} \right) + \left( {ab' + a'b} \right)i$ 

$z.z' = \left( {aa' + bb'} \right) - \left( {ab' + a'b} \right)i$