Answer:
[tex]X = \sqrt{39}[/tex]
Step-by-step explanation:
[tex]1)\ X^2 + 5^2 = Y^2\ (Y\ is\ the\ hypotenuse\ of\ the\ smaller\ triangle)[/tex]
[tex]2)\ Y^2 + 6^2 = 10^2[/tex]
[tex]3)\ X^2 + 25 + 36 = 100[/tex]
[tex]4)\ X^2 = 39[/tex]
[tex]5)\ X = \sqrt{39}[/tex]
