Tìm x ạaaaaaaaaaaaaaa

      `( x + 1/4 )^2 + {11}/{25} = {20}/{25}`

`→ ( x + 1/4 )^2 = {20}/{25} - {11}/{25}`

`→ ( x + 1/4 )^2 = 9/{25}`

`→` \(\left[ \begin{array}{l}x + 1/4 = 3/5\\x + 1/4 = -3/5\end{array} \right.\) 

`→` $\left[\begin{matrix} x = 3/5 - 1/4\\ x = -3/5 - 1/4\end{matrix}\right.$

`→` $\left[\begin{matrix} x = 7/{20}\\ x = -{17}/{20}\end{matrix}\right.$

Vậy `x = 7/{20}`  hoặc  `x = -{17}/{20}`

`@bizco`