¹³/₁₅-³/₄×2¹/₂+¹/₁₂×2¹/₂ = - 0,8
³/₄×2¹/₂ = ³/₄×⁵/₂ = ³ˣ⁵/₄ₓ₂ = ¹⁵/₈
¹/₁₂×2¹/₂ = ¹/₁₂×⁵/₂ = ¹ˣ⁵/₁₂ₓ₂ = ⁵/₂₄
¹³/₁₅ - ¹⁵/₈ = ¹³ˣ⁸/₁₂₀ - ¹⁵ˣ¹⁵/₁₂₀ = ¹⁰⁴⁻²²⁵/₁₂₀ = - ¹²¹/₁₂₀
(-¹²¹/₁₂₀) + ⁵/₂₄ = (-¹²¹/₁₂₀) + ⁵ˣ⁵/₁₂₀ = ⁻¹²¹⁺²⁵/₁₂₀ = -⁹⁶/₁₂₀ = - ⁴/₅ = - 0,8