Verified answer

[tex]\displaystyle\bf\\1)\\\\12,5^{10} \cdot 0,8^{10} =(12,5\cdot 0,8)^{10} =10^{10} =10000000000\\\\\\2)\\\\\frac{6^{11} }{216\cdot6^{9} } =\frac{6^{11} }{6^{3} \cdot 6^{9} } =\frac{6^{11} }{6^{3+9} } =\frac{6^{11} }{6^{12} } =6^{11-12} =6^{-1} =\frac{1}{6}[/tex]