Question

Answer 1

1. \(A=\sqrt{8}+\sqrt{32}-6\sqrt{2}\)

\(=\sqrt{4.2}+\sqrt{16.2}-6\sqrt{2}\)

\(=\sqrt{4}.\sqrt{2}+\sqrt{16}.\sqrt{2}-6\sqrt{2}\)

\(=2\sqrt{2}+4\sqrt{2}-6\sqrt{2}\)

\(=\left(2+4-6\right)\sqrt{2}\)

\(=0\)

Answer 2

Bài 2 

đk x > 0 ; x khác 4 

a, \(B=\dfrac{\sqrt{x}-2+\sqrt{x}+2}{x-4}:\dfrac{\sqrt{x}}{\sqrt{x}+2}=\dfrac{2\sqrt{x}\left(\sqrt{x}+2\right)}{\sqrt{x}\left(x-4\right)}=\dfrac{2}{\sqrt{x}-2}\)

b, \(\Rightarrow\sqrt{x}-2\inƯ\left(2\right)=\left\{\pm1;\pm2\right\}\)

\(\sqrt{x}-2\)	1	-1	2	-2
x	9	1	16	0