bonjour , besoin d aider pour l ex n 9, merci

Bonsoir
A = 10^5 x 10^-12 = 10^-7
B = 10 x 10^-21 x 10^9  = 10 ^-11
C = 2^3 x 5^3 x 10^9 = 10^3 x 10^9 = 10^12
D = 10^-9/10^6 = 10^-15
E = 10^5/10^-2 = 10^7
F = 10^-8 x 10/10^-3 = 10^-7 /10^-3 = 10^ -4
G = (10^13 x 10^-9)² / 10^-14 x 10^-8  = (10^4)² / 10^-6 = 10^8/10^-6 =10^14
H = 64 000 000 x 0.000000001/64 = 0.001 = 10^-3