Exercice 2 :
A = (3V5 + 5V3)^2
A = (3V5)^2 + 2 x 3V5 x 5V3 + (5V3)^2
A = 9 x 5 + 30V15 + 25 x 3
A = 45 + 30V15 + 75
A = 30V15 + 120
B = (5V2 - 3V5)(5V2 + 3V5)
Du genre (a - b)(a + b) = a^2 - b^2
B = (5V2)^2 - (3V5)^2
B = 25 x 2 - 9 x 5
B = 50 - 45
B = 5
Exercice 3 :
C = 1 / (V2 + 5)
C = (5 - V2) / [(5 + V2)(5 - V2)]
C = (5 - V2) / [(5)^2 - (V2)^2]
C = (5 - V2) / (25 - 2)
C = (5 - V2) / 23
D = (3 - V5) / (V8 + 2)
D = [(3 - V5)(2 - V8)] / [(2 - V8)(2 + V8)]
D = (6 - 3V8 - 2V5 + V40) / [(2)^2 - (V8)^2]
D = (6 - 3V8 - 2V5 + 2V10) / (4 - 8)
D = (6 - 3V8 - 2V5 + 2V10) / (-4)
D = (-6 + 3V8 + 2V5 - 2V10) / 4
