第2章 2.7

(1)

(32)2=326+2=526(\sqrt{3}-\sqrt{2})^2 = 3 - 2\sqrt{6} + 2 = 5 - 2\sqrt{6}

(2)

(22+5)2=8+410+5=13+410(2\sqrt{2}+\sqrt{5})^2 = 8 + 4\sqrt{10} + 5 = 13 + 4\sqrt{10}

(3)

(7+2)(72)=72=5(\sqrt{7}+\sqrt{2})(\sqrt{7}-\sqrt{2}) = 7 - 2 = 5

(4)

(15+3)(6012)=(15+3)(21523)=306=24(\sqrt{15}+\sqrt{3})(\sqrt{60}-\sqrt{12}) = (\sqrt{15}+\sqrt{3})(2\sqrt{15}-2\sqrt{3}) = 30 - 6 = 24

解説: r31bn1z