Giúp với SOS

Câu 2
$\displaystyle  \begin{array}{{>{\displaystyle}l}}
a/\ \sqrt{2x\ -\ 3\ } =\ 5\ \ DKXD\ x\ \geqslant \ \frac{3\ }{2\ }\\
\Leftrightarrow \ 2x\ -\ 3\ =\ 25\\
\Leftrightarrow 2x\ =\ 28\\
\Leftrightarrow x\ =\ 14\ tmdk\ \\
b/\ \sqrt{x^{2} +4x+4\ } =\ 1\ DKXD\ x\ \in \ R\ \\
\Leftrightarrow \ x^{2} +4x+4\ =\ 1\\
\Leftrightarrow \ x^{2} \ +\ 4x\ +\ 3\ =\ 0\ \\
\Leftrightarrow \ x^{2} \ +\ 3x\ +\ x\ +\ 3\ =\ 0\ \\
\Leftrightarrow \ ( x+1)( x+3) \ =\ 0\ \\
\Leftrightarrow \left[ \begin{array}{l l}
x=\ -1\ tmdk\  & \\
x=\ -3\ tmdk\  & 
\end{array} \right.\\
\end{array}$