Resolva as operações e indique as respons. notação científica. (7,11cdot 10^5)cdot (12cdot 10^7)= b) (5cdot 10^-4)cdot (2cdot 10^5)= c) (2,16cdot 10^11):(1,2cdot 10^3)= d) (1,8cdot 10^15):(0,9cdot 10^15)= ((0,032cdot 10^10)cdot (8cdot 10^12))/(2cdot 10^18)=

a) $$(7,11\cdot 10^{5})\cdot (12\cdot 10^{7}) = 7,11 \cdot 12 \cdot 10^{5+7} = 84,72 \cdot 10^{12} = 8,472 \cdot 10^{13}$$

b) $$(5\cdot 10^{-4})\cdot (2\cdot 10^{5}) = 5 \cdot 2 \cdot 10^{-4+5} = 10 \cdot 10^{1} = 10^{2} = 100$$

c) $$(2,16\cdot 10^{11}):(1,2\cdot 10^{3}) = \frac{2,16}{1,2} \cdot 10^{11-3} = 1,8 \cdot 10^{8}$$

d) $$(1,8\cdot 10^{15}):(0,9\cdot 10^{15}) = \frac{1,8}{0,9} \cdot 10^{15-15} = 2 \cdot 10^{0} = 2$$

e) $$\frac {(0,032\cdot 10^{10})\cdot (8\cdot 10^{12})}{2\cdot 10^{18}} = \frac{0,032 \cdot 8}{2} \cdot 10^{10+12-18} = 0,128 \cdot 10^{4} = 1,28 \cdot 10^{3}$$