Question

giúp câu 5 và 6

Answer 1

`5)\sqrt{(7+2\sqrt2)^2}-\sqrt{9+4\sqrt2}`
`=7+2sqrt2-\sqrt{8+2.2sqrt2+1}`
`=7+2sqrt2-\sqrt{(2sqrt2+1)^2}`
`=7+2sqrt2-2sqrt2-1`
`=6`

Answer 2

 \(\sqrt{\left(7+2\sqrt{2}\right)^2}-\sqrt{9+4\sqrt{2}}\\ =\left|7+2\sqrt{2}\right|-\sqrt{8+2.2\sqrt{2}.1+1}\\ =7+2\sqrt{2}-\sqrt{\left(2\sqrt{2}+1\right)^2}\\ =7+2\sqrt{2}-\left|2\sqrt{2}+1\right|\\ =7+2\sqrt{2}-2\sqrt{2}-1\\ =6\)

 

Answer 3

5: Ta có: \(\sqrt{\left(7+2\sqrt{2}\right)^2}-\sqrt{9+4\sqrt{2}}\)

\(=7+2\sqrt{2}-2\sqrt{2}-1\)

=6