Répondre :
B = 24*10^12 * 10^-5 24*10^7
--------------------------- = ------------------------- = 3 *10^-1 = 0.3
8*10^10 8*10^10
B = 24*10^12 * 10^-5 24*10^7
--------------------------- = ------------------------- = 3 *10^-1 = 0.3
8*10^10 8*10^10