What are the complex formulas?

1, the law of additive association: (a+bi)+(c+di) = (a+c)+(b+d) i.

2. Binding law: z1+z2 = z2+z1; (z 1+z2)+z3 = z 1+(z2+z3)

3. The product of two complex numbers: (a+bi) (c+di) = (ac-bd)+(bc+ad) i.

4. Complex numbers of * * * yoke: modules of a+bi and a-bi complex numbers Z = a+bi, _ z _ = √ (A 2+B 2).