Hello, thank you for taking the time to post your question!
The starting point on a question like this would be finding the derivative of the function then setting it equal to the indicated slope value.
So the derivative of the function here would be dy/dx = 2 / (x^2 – 1)
Setting that equal to 0.25 and then solving I get
2 / (x^2 – 1) = 0.25
2 = 0.25x^2 – 0.25
2.25 = 0.25x^2
9 = x^2
x = -3 and x = +3
I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)