bonjour
A = ( 1 + √2)²
= 1 + 2√2 + 2
= 3 + 2 √2
B = ( 2 + √3 ) ( 2 - √3)
= 4 - 3 = 1
C = ( 2 √3 - 4 )²
= 12 - 16 √3 + 16
= 28 - 16 √3
D = ( 2 + 3 √5)²
= 4 + 12 √5 + 45
= 49 + 12 √5