Question

alguém pode me ajudar?

Answer 1

Olá!
 
a)

$5\cdot 10^9\times 3\cdot 10^7=5\times 3\cdot 10^{9+7}=15\cdot 10^{16}.$


b)

$3,4\cdot 10^9\times 4\cdot 10^5 = 34\cdot 10^8\times 4\cdot 10^5 = 34\times 4\cdot 10^{8+5}=\\ \\ = 136\cdot 10^{13}.$

c)

$8,41\cdot 10^5\times 3,2\cdot 10^7 = 841\cdot 10^3\times 32\cdot 10^6 = \\ \\ = 841\times 32\cdot 10^{3+6}=26912\cdot 10^9 = 2,6912\cdot 10^{13}.$

d)

$90\cdot 10^6\div 9\cdot 10^4=90\div 9\cdot 10^{6-4} = 10\cdot 10^2 = \\ \\ =10^{1+2}=10^3 = 1000.$



Bons estudos!