Answer: x=5 square root 2/2
Explanation
Use Pythagorean theorem
x^2 + x^2 = 5^2
Combine like terms and solve right side
2x^2=25
Divide by 2
x^2=25/2
Square root both sides
x= square root of 25/2
Simplify
x=5/square root of 2
Rationalize
x=5 square root of 2/2