qn 約1個月以前 11¹⁰ = (10+1)¹⁰ = C¹⁰₁₀·10¹⁰ + C¹⁰₉·10⁹ + ⋯ + C¹⁰₃·10³ + C¹⁰₂·10² + C¹⁰₁·10 + C¹⁰₀·1 = 1000 (10⁷C¹⁰₁₀ + ⋯ + C¹⁰₃) + 100C¹⁰₂ + 10C¹⁰₁ + C¹⁰₀ = 1000 (10⁷C¹⁰₁₀ + ⋯ + C¹⁰₃) + 100·45 + 10·10 + 1 = 1000 (10⁷C¹⁰₁₀ + ⋯ + C¹⁰₃ + 4) + 601 留言