Answer:
Raymond's mistake was on the last step, since he didn't square root both sides
The correct answer should be
[tex]c = \sqrt{41}[/tex]
Step-by-step explanation:
[tex]a^2 + b^2 = c^2\\4^2 + 5^2 = c^2\\16 + 25 = c^2\\c^2 = 41\\c = \sqrt{41}[/tex]
Good luck!