6) 25⁴ ⋅ 125¹⁰ / 5³⁷.

6) $$ \frac{25^4 \cdot 125^{10}}{5^{37}} = \frac{(5^2)^4 \cdot (5^3)^{10}}{5^{37}} = \frac{5^8 \cdot 5^{30}}{5^{37}} = \frac{5^{38}}{5^{37}} = 5^{38-37} = 5^1 = 5 $$

Ответ: 5