bonsoir,
exercice 2 :
A = √18-√8+√50-√32-√98
=3√2 - 2√2 + 5√2 - 4√2 - 7√2
= -5√2
B = 3√72-√8+√50-√32-√98
= 6√2 - 2√2 + 5√2 - 4√2 - 7√2
= -2√2
C = 5√300-2√12+√363
= 50√3 - 4√3 + 11√3
= 57√3
Exercice 3
D = (√5 + √7)²
= 5 + 2 x √5 x √7 + 7
= 5 + 2√35 + 7
= 12 + 2√35
E = (√7 - 1)²
= 7 - 2 x √7 x 1 + 1
= 7 - 2√7 + 1
= 8 - 2√7
F = (2√2-3)(2√2+3)
= 8 + 6√2 - 6√2 - 9
= -1
G = (3√2+2√3)²
= 18 + 2 x 3√2 x 2√3 + 12
= 18 + 12√6 + 12
= 12√6 + 30
Exercice 4
1) H = (√3-√2)² - (√5-1)(√5+1)
= 3 - 2 x √3 x √2 + 2 - 5 + 1
= 3 - 2√6 + 2 - 5 + 1
= - 2√6 + 1
2) I = √40-√160+2√250
= 2√10 - 4√10 + 10√10
= 8√10