Question

Помогите решить 2x+4-√(x+2)=15

Answer 1

$2x+4- sqrt{x+2} =15$
$- sqrt{x+2} =15-4-2x$
$- sqrt{x+2} =11-2x$
$sqrt{x+2} =2x-11$
$left { {{2x-11 geq 0} atop {( sqrt{x+2})^2=(2x-11)^2 }} right.$
$left { {{2x geq 11} atop {x+2=4x^2-44x+121 }} right.$
$left { {{x geq 5,5} atop {4x^2-45x+119=0 }} right.$
$4x^2-45x+119=0$
$D=(-45)^2-4*4*119=2025-1904=121$
$x_1= frac{45+11}{8} =7$
$x_2= frac{45-11}{8} =4,25$  - ∅
Ответ: $7$