Fig. shows circles which are just touching. Find x by using pythagoras theorem.
I believe they're tangential circles.
Here's the figure:
p.s. i am a bit bad at drawing on pc. :P
It regrettable that you did not pickup on Krizalid’s suggestion.
I do not think that he misunderstood the x (though I wish he had used say y).
That is the horizontal distance between the centers in terms of the radii: $\displaystyle 2\sqrt {Rr} $.
Now the x in the original problem is $\displaystyle R + 2\sqrt {Rr} + r = \left( {\sqrt R + \sqrt r } \right)^2 $.
That is an elegant formula.
Note: $\displaystyle \left( {\sqrt {25} + \sqrt {7.5} } \right)^2 = {\rm{59}}{\rm{.8861278752583}}$
After being able to solve few similar problems, I'm stuck again on a problem of somewhat similar nature.
I can't seem to comprehend this circles tangent thing I assume. Here I have to find h using pythagoras theorem again.
Attached is the image of circles.