Та Татьяна Ответ R = R1*R2 /(R1+R2) => R * (R1 + R2) = R1*R2 R*R1 + R*R2 - R1*R2 = 0 R1*R2 - R1*R = R*R2 R1 * (R2 - R) = R*R2 R1 = R*R2 / (R2 - R)