312₅ = 3 ⋅ 5² + 1 ⋅ 5¹ + 2 ⋅ 5⁰ = 3 ⋅ 25 + 1 ⋅ 5 + 2 ⋅ 1 = 75 + 5 + 2 = 82
Ответ: 312₅ = 3 ⋅ 5² + 1 ⋅ 5¹ + 2 ⋅ 5⁰ = 82₁₀