Svp aider moi Je suis dans la galère ! Merci infiniment d avance

Bonsoir

A = [ 1.8 x 10^-4 x 28 x 10^-5 ] / [ 168 x (10^3)^2 ]
= [ 1.8 x 28 x 10^-4-5 ] / [ 168 x 10^3x2 ]
= [ 50.4 x 10^-9 ] / [ 168 x 10^6 ]
= (50.4 / 168) x (10^-9 / 10^6)
= 0.3 x 10^-9-6
= 0.3 x 10^-15
= 3 x 10^-1 x 10^-15
= 3 x 10^-1-15
= 3 x 10^-16

B = [ 7.2 x 10^-6 x 18 x 10^7 ] / [ 192 x (10^-10)^2 ]
= [ 129.6 x 10^1 ] / [ 192 x 10^-20 ]
= (129.6 / 192) x (10^1 / 10^-20)
= 0.675 x 10^21
= 6.75 x 10^-1 x 10^21
= 6.75 x 10^20

C = [ 2700 x 10^-9 x 40 x 10^-2 ] / [ 0.3 x (10^-9)^3 ]
= [ 108000 x 10^-11 ] / [ 0.3 x 10^-27 ]
= (108000 / 0.3) x (10^-11 / 10^-27)
= 360000 x 10^16
= 3.6 x 10^5 x 10^16
= 3.6 x 10^21

D = [ 0.36 x 10^-6 x 0.45 x 10^-10 ] / [ 0.4 x (10^3)^5 ]
= [ 0.162 x 10^-16 ] / [ 0.4 x 10^15 ]
= (0.162 / 0.4) x (10^-16 / 10^15)
= 0.405 x 10^-31
= 4.05 x 10^-1 x 10^-31
= 4.05 x 10^-32

Voilà j'espère avoir pu t'aider ^^