ab/c = (α+β+γ)(α*β+β*γ+γ*α) / (α*β*γ)
= {(α+β)*α*β+(β+γ)*β*γ+(γ+α)*γ*α} / (α*β*γ) + 3
= (α+β)/γ+(β+γ)/α+(γ+α)/β + 3
= (α/β + β/α) + (β/γ + γ/β) + (γ/α + α/γ) + 3
≧ 2 + 2 + 2 + 3
= 9