Question

[Oo Bản tình ca ác quỷ oO]

1/ rút gọn:

\(\sqrt{\left(a^2+\frac{4}{a^2}\right)^2-8\left(a+\frac{2}{a}\right)^2+48}\)  (a\(\ne\)0)

giúp mjk nha m.n!!! thks nhìu!!

Answer 1

[Bá đạo sever là tao]

đặt \(t=a+\frac{2}{a}\)

Answer 2

[vu tien dat]

Đặt \(b=a+\frac{2}{a}\Rightarrow b^2=a^2+4+\frac{4}{a^2}\Rightarrow a^2+\frac{4}{a^2}=b^2-4.\)

\(\Rightarrow A=\sqrt{\left(b^2-4\right)^2-8b^2+48}\)

\(=\sqrt{b^4-16b^2+64}\)

\(=\sqrt{\left(b^2-8\right)^2}=\left|b^2-8\right|\)

\(=\left|a^2+\frac{4}{a^2}-4\right|=\left|\left(a-\frac{2}{a}\right)^2\right|=\left(a-\frac{2}{a}\right)^2\)