Exercice 1 svp pout demain

Exercice 1: 
A= (2/5)*(11/25)+((1/4)-(1/8))
  =22/125+1/8
  =301/1000
B=25/4/12/4
  =25/4/3
  =(25*3)/(4*1)
  =75/4
C=(2^4*5^2*3^12)/(2^-2*3^5*5*^4)
  =(16*25*531441)/((1/4)*243*625)
  =212576400/(151875/4)
  =139968/25
D=2^2^2
  =2^4
  =2*2*2*2
  =16
Exercice 2 : 
On applique la relation v=d/t  <=>  t=d/v
Application numérique:
t=149600000/300000
t=498
 =4.98*10^2 s