[tex]dane:\\P_1 = 100 \ W\\U_1 = 230 \ W\\U_2 = 200 \ V\\szukane:\\P_2 = ?\\\\Rozwiazanie\\\\P = U\cdot I = \frac{U^{2}}{R}\\\\P_1 = \frac{U_1^{2}}{R} \ \ \rightarrow \ \ R = \frac{U_1^{2}}{P_1}\\oraz\\R = \frac{U_2^{2}}{P_2}\\\\\frac{U_1^{2}}{P_1} = \frac{U_2^{2}}{P_2}\\\\P_2\cdot U_1^{2} = P_1\cdot U_2^{2}} \ \ /: U_1^{2}}\\\\P_2 = P_1\cdot\frac{U_2^{2}}{U_1^{2}}=P_1\cdot(\frac{U_2}{U_1})^{2}[/tex]
[tex]P_2 = 100 \ W\cdot(\frac{200V}{230V})^{2}\\\\P_2 = 75,6 \ W[/tex]
Odp. Szukana moc P₂ = 75,6 W.
