{
U = I * R
I = E / ( R + r )
}
U1 = I1 * R1 => I1 = U1 / R1
U2 = I2 * R2 => I2 = U2 / R2
E = I1/(R1 + r) (1)
E = I2/(R2 + r) (2)
{
se imparte (1) la (2)
}
1 = [tex] \frac{I1(R2 + r)}{I2(R1 + r)} [/tex]
I1(R2 + r) = I2(R1 + r)
I1R2 + I1r = I2R1 + I2r
I1R2 - I2R1 = r(I2 - I1)
r = [tex]\frac{I1R2-I2R1}{I2-I1}[/tex]
r = [tex]\frac{1*6 - 0.75 * 4}{ 1-0.75}[/tex]
r = 3/0.25
r = 12 ohmi
E = 1(4+12)
E = 16 V