Answer:
x = 15
Step-by-step explanation:
Use pythagorean theorem: [tex]a^{2} +b^{2} = c^{2}[/tex]
[tex]8^{2} +x^{2} =17^{2} \\ 64 + x^{2} = 289 \\\\x^{2} = 289 - 64\\x^{2} = 225\\x = 15[/tex]
