chị giỏi quá

3 - \(2\sqrt{2}\)

= 3 - 2,83

= 0,17

4 + \(2\sqrt{3}\)

= 4 + 3,46

= 7,46

4 - \(2\sqrt{3}\)

= 4 - 3,46

= 0,54

a. (x - 1,3)² = 9

<=> (x - 1,3)² - 9 = 0

<=> (x - 1,3)² - 3² = 0

<=> (x - 1,3 - 3)(x - 1,3 + 3) = 0

<=> (x - 4,3)(x + 1,7) = 0

<=> \(\left[{}\begin{matrix}x-4,3=0\\x+1,7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4,3\\x=-1,7\end{matrix}\right.\) 

bay accc

out play nó