(⁴/₁₅-³/₁₀) : 1³/₄₀ + (-2⁴/₁₉) × (¹/₃+⁴/₇) ≈ - 2,03
⁴/₁₅-³/₁₀ = ⁴ˣ²/₃₀ -³ˣ³/₃₀ = ⁸⁻⁹/₃₀ = - ¹/₃₀
- ¹/₃₀ : 1³/₄₀ = - ¹/₃₀ ÷ ⁴³/₄₀ = - ¹/₃₀ × ⁴⁰/₄₃ = -¹ˣ⁴⁰/₃₀ₓ₄₃ =- ⁴/₃ₓ₄₃ = - ⁴/₁₂₉
¹/₃+⁴/₇ = ¹ˣ⁷/₂₁ + ⁴ˣ³/₂₁ = ⁷⁺¹²/₂₁ = ¹⁹/₂₁
(-2⁴/₁₉) × ¹⁹/₂₁ =(-⁴²/₁₉) × ¹⁹/₂₁ = - ⁴²ˣ¹⁹/₂₁ₓ₁₉ = - ⁴²/₂₁ = - 2
- ⁴/₁₂₉ - 2 = - 2⁴/₁₂₉ ≈ - 2,03