10^6/10^4x10^7 merci 10^2x10^-7x10/10^3x(10^-2)^4
10^6/10^4)*10^7= 1000000000 = 10^9
10^2x10^-7x10/10^3x(10^-2)^4 =10^-15
10^6/10^4)*10^7
=1000000000
=10^9
10^2x10^-7x10/10^3x(10^-2)^4
=10^-15
