salut
[img]http://latex.codecogs.com/gif.download?on\&space;a\&space;D=\left&space;\{&space;x\ni&space;\mathbb{R}/2x+11\geq&space;0\&space;et\&space;2x-1\geq&space;0&space;\right&space;\}\\\\donc\&space;D=\&space;\left[\frac{1}{2},+\infty&space;\right&space;[\\\\on\&space;a\&space;\sqrt{2x+11}=2+\sqrt{2x-1}\Leftrightarrow&space;2x+11=4+2x-1+4\sqrt{2x-1}\\\\donc\&space;\sqrt{2x-1}=2\\\\d'o%C3%B9\&space;x=\frac{5}{2}[/img]