[tex]a) 2 \sqrt{5}(3+ \sqrt{5})=6\sqrt5+10 \\
b) 3\sqrt2(2\sqrt3- \sqrt{2}=6\sqrt6-6 \\
c) (2-\sqrt3)(1+\sqrt2)= 2+2\sqrt2-\sqrt3-\sqrt6 \\
d)(\sqrt3+1)(\sqrt3-1)=(\sqrt3)^2-1^2=3-1=2 \\
e)(2\sqrt2-3)(2\sqrt2+3)=(2\sqrt2)^2-3^2=8-9=-1 \\
f)(2+\sqrt3)^2=4+4\sqrt3+(\sqrt3)^2=4+4\sqrt3+3=7+4\sqrt3 \\
g)\sqrt3-1)^2=(\sqrt3)^2-2\sqrt3+1=3-2\sqrt3+1=4-2\sqrt3[/tex]