R₁₊₂ = R₁ + R₂ = 5 + 4 = 9 Ом
R₃₊₆ = R₃·R₆/(R₃+R₆) = 3·5/(3+5) = 15/8 Ом
R₄₊₅ = R₄·R₅/(R₄+R₅) = 3·4/(3+4) = 12/7 Ом
R₃₊₄₊₅₊₆ = R₃₊₆ + R₄₊₅ = 15/8 + 12/7 = (15·7+12·8)/(8·7) = (105+96)/56 = 201/56 Ом
Rэкв. = R₁₊₂·R₃₊₄₊₅₊₆/(R₁₊₂+R₃₊₄₊₅₊₆) = (9·201/56)/(9 + 201/56) ≈ 2,6 Ом
U₁₂ = I₁·R₁₊₂ = 5·9 = 45 В
U₆ = R₃₊₆/R₃₊₄₊₅₊₆ · U₁₂ = (15/8)/(201/56) · 45 = (15·56)/(8·201) · 45 = 1575/67 В
I₆ = U₆/R₆ = (1575/67)/5 = 315/67 ≈ 4,7 А