Câu 2 (1,0 điểm): Tìm x, biết: a) $\sqrt{16}$ - x = $\sqrt{9}$ b) x.$\sqrt{\frac{1}{25}}$ = 1

`a . ` `\sqrt{16}-x=\sqrt{9}`

`=>` `\sqrt{4^2}-x=\sqrt{3^2}`

`=>` `4-x=3`

`=>` `x=4-3`

`=>` `x=1`

Vậy `x=1`

$\\$

`b . ` `x*\sqrt{1/25}=1`

`=>` `x*\sqrt{(1/5)^2}=1`

`=>` `x*1/5=1`

`=>` `x=1:1/5`

`=>` `x=5`

Vậy `x=5`

`#me`