Ответ:\((6^4)^4:(6^5)^3=6^{16-15}=6\).\(8^3:4^4=2^9:2^8=2\).\(7^{14+6-18-2}=1\).\(5^{6+6-10}=5^2=25\).\(21^8:21^7=21\).\((5^9\cdot 2^{12})/(2^{12}\cdot5^6)=5^3=125\).