TITLE: How to solve problems involving roots. $\sqrt{(x+3)-4\sqrt{x-1}} + \sqrt{(x+8)-6\sqrt{x-1}} =1$
QUESTION [5 upvotes]: How to solve problems involving roots. If we square them they may go to fourth degree.There must be some technique to solve this.
$$\sqrt{(x+3)-4\sqrt{x-1}} + \sqrt{(x+8)-6\sqrt{x-1}} =1$$

REPLY [5 votes]: Straight, you can get the following equation : 
$$
\sqrt{(2-\sqrt{x-1})^2} + \sqrt{(3-\sqrt{x-1})^2} =1
$$
which leads to the following equation :
$$
|2-\sqrt{x-1}| + |3-\sqrt{x-1}| =1
$$
Then you will have three cases to discuss :

case : $\sqrt{x-1} \leq2$  (equivalent to $x\leq5$) :

$\sqrt{x-1} = 2$ then $x = 5$

case : $\sqrt{x-1} >2$ and $\sqrt{x-1} <3$  (equivalent to $5<x<10$) :

The equation below can be written : 
$$
\sqrt{x-1}-2 + 3-\sqrt{x-1} =1
$$
equivalent to :
$
1=1
$
The solutions belongs to $]5,10[$

case : $\sqrt{x-1} \geq3$  (equivalent to $x\geq10$) :

$\sqrt{x-1} = 3$ then $x = 10$
The solutions belongs to $[5,10]$

REPLY [2 votes]: $$\sqrt{(x+3)-4\sqrt{x-1}} + \sqrt{(x+8)-6\sqrt{x-1}} =1$$
 
Put x-1 = t^2 
so the equation becomes 
$$\sqrt{t^2+4-4t} + \sqrt{t^2+9-6t} =1$$
complete the squares . 
EDIT: 
My answer was incorrect. Thanks to egreg and Samatix.