(3\sqrt{2}+2\sqrt{5})(3\sqrt{2}-2\sqrt{5})=(3\sqrt{2})^2-(2\sqrt{5})^2=9*2-4*5=-2
(\sqrt{6}+2\sqrt{3})^2=(\sqrt{6})^2+2*\sqrt{6}*2\sqrt{3}+(2\sqrt{3})^2=6+4\sqrt{18}+4*3=4\sqrt{18}+18=4\sqrt{2*9}+18=4*3\sqrt{2}+18=12\sqrt{2}+18
(3\sqrt{7}-\sqrt{2})^2=(3\sqrt{7})^2-2*3\sqrt{7}*\sqrt{2}+(\sqrt{2})^2=9*7-6\sqrt{14}+2=65-6\sqrt{14}
w d) 3√do potegi 3 ??? pierwiastek z ilu???