Question

\(\left(\sqrt{28}-2\sqrt{14}+\sqrt{7}\right)\sqrt{7}+7\sqrt{8}\)

Answer 1

Bạn ơi ! Cho mình hỏi,đề bài yêu cầu gì vậy bạn ?

Answer 2

\(\left(\sqrt{28}-2\sqrt{14}+\sqrt{7}\right)\sqrt{7}+7\sqrt{8}\)

\(=\left(2\sqrt{7}-2\sqrt{14}+\sqrt{7}\right)\sqrt{7}+7\sqrt{8}\)

\(=14-14\sqrt{2}+7+7\sqrt{8}\)

\(=21-14\sqrt{2}+14\sqrt{2}=21\)