Question

Помогите прошу!!!!
(√3-√7)^2*(10+2√21)=

Answer 1

 $(\sqrt{3}-\sqrt{7})^2*(10+2\sqrt{21})=$

$=((\sqrt{3})^2-2*\sqrt{3}*\sqrt{7}+(\sqrt{7})^2)*(10+2\sqrt{21})=$

$=(3-2\sqrt{21}+7)*(10+2\sqrt{21})=$

$=(10-2*\sqrt{21})*(10+2\sqrt{21})=$

$=10^2-(2*\sqrt{21})^2=$

$=100-2^2*21=100-4*21=100-84=16$

Ответ: 16