A=1-√2
A²=(1-√2)²
=1-2√2+2
=3+2√2
B=[tex]\frac{3-\sqrt{18} }{3-2\sqrt{2} } =\frac{(3-\sqrt{18})(3+2\sqrt{2}) }{(3-2\sqrt{2})(3+2\sqrt{2} ) }[/tex]
=[tex]\frac{9+6\sqrt{2}-3\sqrt{18}-2\sqrt{2*18} }{9-8} =\frac{9+6\sqrt{2}-3*3\sqrt{2}-2*3\sqrt{2*2} }{1}[/tex] car √18=3√2
=9+6√2-9√2-6*2
=9-12+6√2-9√2
= -3-3√2
* veut dire multiplication