Hello, TriKri!
I too got a fourthdegree equation, too.
But there is a way around it . . .
[quote]A 10m ladder is leaned against a box (1 x 1 x 1 m) placed against a wall.
But the ground is so slippery that the ladder falls over the box and leans against the wall.
How high up on the wall does the ladder reach? Code:

*
* y
10 *    *
*  1 
* 1 1
*  
*        *    *
x 1
From the large right triangle: . .[1]
The two smaller right triangles are similar.
. . So we have: . .[2]
Substitute [2] into [1]: .
and we have: .
. .
. .
Let
. . and we have the quadratic: .
Use the Quadratic Formula to solve for ,
. . then backsubstitute and solve for