1) $$2^{18}: (2^7)^2 = 2^{18}: 2^{14} = 2^{18-14} = 2^4 = 16$$
2) $$(7^8)^{\frac{7}{8}}: (7^3)^5 = 7^{8 \cdot \frac{7}{8}} : 7^{15} = 7^7 : 7^{15} = 7^{7-15} = 7^{-8} = \frac{1}{7^8}$$
3) $$11^5\cdot (11^3)^7: 11^{26} = 11^5\cdot 11^{21}: 11^{26} = 11^{5+21-26} = 11^0 = 1$$
4) $$9^2\cdot 27 = (3^2)^2 \cdot 3^3 = 3^4 \cdot 3^3 = 3^{4+3} = 3^7 = 2187$$
5) $$\frac{6^{12}\cdot (6^3)^5}{(6^5)^4 \cdot 6^4} = \frac{6^{12}\cdot 6^{15}}{6^{20} \cdot 6^4} = \frac{6^{27}}{6^{24}} = 6^{27-24} = 6^3 = 216$$
6) $$\frac{25^4\cdot 125^{10}}{5^{37}} = \frac{(5^2)^4\cdot (5^3)^{10}}{5^{37}} = \frac{5^8 \cdot 5^{30}}{5^{37}} = \frac{5^{38}}{5^{37}} = 5^1 = 5$$
Ответ: 1) 16; 2) $$\frac{1}{7^8}$$; 3) 1; 4) 2187; 5) 216; 6) 5