a)
(3\sqrt2+2\sqrt5)(3\sqrt2-2\sqrt5)=(3\sqrt2)^2-(2\sqrt5)^2=9*2-4*5=18-20=-2
b)
(3\sqrt7-\sqrt2)^2=(3\sqrt7)^2-2*3\sqrt7*\sqrt2+(\sqrt2)^2=9*7-6\sqrt{14}+2=65-6\sqrt{14}
c)
(\sqrt6+2\sqrt3)^2(\sqrt6)^2+2*\sqrt6*2\sqrt3(2\sqrt3)^2=6+4\sqrt{18}+4*3=6+4\sqrt{9*2}+12=
18+4*3\sqrt2=18+12\sqrt2
d)
(2\sqrt[3]3+3\sqrt[3]2)^2=(2\sqrt[3] {3})^2+2*2\sqrt[3]{3}*3\sqr[3]2+(3\sqrt[3]2)^2=4\sqrt[3]{3^2}+12\sqrt[3]6+9\sqrt3{2^2}=
4\sqrt[3]9+12\sqrt[3]6+9\sqrt[3]4