Sagot :
Réponse :
a. 3 x 10^3 x 80 x 10^5 = 3 x 8 x 10 x 10^3 x 10^5
= 24 x 10^(1+3+5)
= 2.4 x 10 x 10^9
= 2.4 10^10
b. 50 x 10^3 x 2 x 10^5 = 5 x 10 x 2 x 10^3 x 10^5
= 10 x 10 x 10^3 x 10^5 = 10^(1+1+3+5)
= 10^10
C. 3 x 10^8 x 5 x 10^(-7 ) =15 x 10^8 x 10^(-7) = 1.5 x 10 x 10^8 x 10^(-7)
= 1.5 x 10^(1+8-7) = 1.5 x 10²
d. 3 x 10^10 x 7 x 10^(-6 ) = 21 x 10^10 x 10^(-6) = 2.1 x 10 x 10^10 x 10^(-6)
= 2.1 x 10^(1+10-6) = 2.1 x 10^5
e. -3 x 10^2 x 1 x 10^(-5 ) = -3 x 10^(2-5) = -3 x 10^(-3)
f. 5 x 10^6 x 0,3 x 10^(-6) = 1.5 x 10^6 x 10^(-6) = 1.5 x 10^(6-6) = 1.5 x 10^0
= 1.5
j'espère avoir aidé