#### Answer

x = $\sqrt 26 w$

#### Work Step by Step

Since the triangle is a right angle triangle we use the pythagorean theorem.
$a^{2} + b^{2} = c^{2}$
In this problem a=5w, b=w and c= x
$(5w)^{2} + (w)^{2} = x^{2}$
$ 5w \times 5w + (w)^{2} = x^{2}$
$25w^{2} + w^{2} = x^{2}$
$26w^{2} = x^{2}$
We take square root of both sides
$\sqrt (26w^{2}) = \sqrt x^{2}$
$\sqrt 26 w$ = x
Therefore x = $\sqrt 26 w$