bonjour voila mon devoir !!a tout de suite :* http://nosdevoirs.fr/devoir/673977

A= (√3-5) (√3 +5)
(√3)²-(5)²
=3-25
=-22
B= (√17 -8)(√17+8)
=(√17)²-(8)²
=17-64
=-47
C= (6-√7)(6+√7)
=(6)²-(√7)²
=36-7
=29
D=(√13-5)
=-5+√13
E=(√3-√2)(√3+√2)
=(√3)²-(√2)²
=3-2
=1
F= (5-√8)²
5²-2x5x√8 +√8²
25-20√2 +8
=33-20√2
G=(-3+√11)²
=-3²+2x-3x√11 +√11²
=-9-6√11 +11
=2-6√11
H=(√11+√7)(√11-√7)
(√11)²-(√7)²
11-7
=4