Question

[Hà Phạm Như Ý]

Rút gọn:

\(A=\sqrt{63}-2\sqrt{175}+\sqrt{252}-\frac{1}{7}\sqrt{28}\)

Answer 1

[Phạm Đức Nam Phương]

\(A=\sqrt{9.7}-2\sqrt{25.7}+\sqrt{9.7.4}-\frac{1}{7}\sqrt{4.7}\)

\(=3\sqrt{7}-10\sqrt{7}+6\sqrt{7}-\frac{2}{7}\sqrt{7}\)

\(=\frac{-9}{7}\sqrt{7}\)

Nếu đúng tk nhé

Answer 2

[Nguyễn Điệp Hương]

a = \(\sqrt{63}-2\sqrt{175}+\sqrt{252}-\frac{1}{7}\sqrt{28}\)

  = \(\sqrt{\frac{4}{7}}\left(1,5-5+3-1\right)\)

 =  \(-1,5\sqrt{\frac{4}{7}}\)