[tex]6^{7}\cdot(6^{2})^{8}:6^{2} = 6^{7}\cdot6^{2\cdot8}:6^{2} = 6^{7}\cdot6^{16}:6^{2} = 6^{7+16}:6^{2} = 6^{23}:6^{2} = 6^{23-2} = 6^{21}\\\\27^{3}\cdot3^{9}:9^{4} = (3^{3})^{3}\cdot3^{9}:(3^{2})^{4} = 3^{3\cdot3}\cdot3^{9}:3^{2\cdot4} = 3^{9}\cdot3^{9}:3^{8} = 3^{9+9-8} = 3^{10}[/tex]
[tex]17\cdot10^{12}\cdot2,1\cdot10^{6} = 1,7\cdot10\cdot10^{12}\cdot2,1\cdot10^{6} = 1,7\cdot2,1\cdot10^{1+12+6} = 3,57\cdot10^{19}\\\\0,0000000026 = 2,6\cdot10^{-9}\\\\2988000000 = 2,988\cdot10^{9}[/tex]
