Réponses

2014-02-10T20:48:59+01:00
Bonsoir
1a)
(2 + V3)(2 - V3) = 2² - (V3)² = 1 
b)
1/(2 + V3) = (2 - V3) / (2 + V3)(2 - V3) = 2-V3
c)
(4-2V3)/(2+V3) = (4-2V3)(2-V3) /  ( 2+V3)(2-V3 ) = 8-4V3-4V3+6 = 14 -8V3 
2)
2/(3+V11) = (2(3-V11)) / ((3+V11)(3-V11)) = (6-2V11)/(9-11) = -3+V11 

(5+2V7)/(5-2V7) = ((5+2V7)(5+2V7)) / ((5-2V7)(5+2V7)) = (25+28+20V7)/(25-28) = (53+20V7)/ -3 = (-53-20V7) / 3 

(2+3V5)/(2V5-3) = (2+3V5)(2V5+3) / (2V5-3)(2V5+3) = 
(4V5+6+30+9V5) / 20-9 = (36+13V5) / 11