Merci de m'aider A=(√8+1)² B=(√3-1)(√3+1) C=(2-√6)² D=(√5+2)(√5-2)

A=(√8+1)²=(√8)²+2*√8*1+1²=9+4√2
B=(√3-1)(√3+1)=(√3)²-1²=2
C=(2-√6)²=2²-2*2*√6+(√6)²=10-4√6
D=(√5+2)(√5-2)=(√5)²-2²=1

Bonsoir Gratho

[tex]A=(\sqrt{8}+1)^2\\\\A=(\sqrt{8})^2+2\times\sqrt{8}\times1+1^2\\\\A=8+2\sqrt{8}+1\\\\\boxed{A=9+2\sqrt{8}}\\\\ B=(\sqrt{3}-1)(\sqrt{3}+1)\\\\B=(\sqrt{3})^2-1^2\\\\B=3-1[/tex]

[tex]\\\\\boxed{B=2}[/tex]

[tex]C=(2-\sqrt{6})^2\\\\C=2^2-2\times2\times\sqrt{6}+(\sqrt{6})^2\\\\C=4-4\sqrt{6}+6\\\\\boxed{C=10-4\sqrt{6}}\\\\D=(\sqrt{5}+2)(\sqrt{5}-2)\\\\D=(\sqrt{5})^2-2^2\\\\D=5-4\\\\\boxed{D=1}[/tex]