I = I_R + I_C = 4 + j3

$$R = \frac{U}{I_{R}} = \frac{100}{4} = 25\ $$

$$\text{jX}_{C} = \frac{U}{I_{C}} = \frac{100}{3} = - 33,33j$$

$$Z_{2} = \frac{R \bullet jXc}{R + jXc} = \frac{25 \bullet ( - j33,33)}{25 + ( - j33,33)} = 16 - j12$$

Z_z = Z + Z₂ = (3+j4) + (16−j12) = 19 − j8

U = I • Z_z = (4+j3) • (19−j8) = 100 + j25

S = UI^* = (100+j25) • (3−j4) = 475 − j200 ∖ n