Найдите значение выражения 2 ⋅ √ 15 ⋅ 7 √ 5 ⋅ 21 2 ⋅ 15 ⋅ 7 ‾ ‾ ‾ ‾ ‾ ‾ √ 5 ⋅ 21 ‾ ‾ ‾ ‾ ‾ ‾ √ .