Réponses

2013-04-07T21:35:39+02:00

A = 2/4 -1/4 : 20/5 +1/5 =  1/4 : 21/5 = 1/4 x 5/21 = 5/84

 

B = 3/4 - 2/20 = 15/20 -2/20 = 13/20

 

C = 5 x 12 x 10 : 3 x 10^5 = 60 x 10 : 3 x 10^5 = 60/3 x 10^-4 = 20 x 10^-4 = 2 x 10^-3

 

D = (2 +3V5)(2-3V5) = (2+3V5)² - (2-3V5)² = (4+45)- (4-45) = 49+41 = 90

 

E = V 3 x 5² -2V3x2² +2V3x3² = 5V3 -6V3+6V3 = 5V3