Efetue as operações a seguir: a) 6.105.12.109 = b) 8.102. 3.10-2 = c) 9.109. 2 . 105. 12,5.10-6 = d) 9 .108/ 3 . 10-3 = e) 9 . 108/ 2 . 105 = f) 99 . 10-8/ 99 . 10-8 = g) 9.108/ 18.10-3.0,5.108 =