For what value(s) of x is the fraction 5x-10/x^2-25 undefined?

+5 or -5.

Step-by-step explanation:

Given equation,

5x-10/x^2-25

When you divide something with zero, it becomes undefined. So, to be undefined, x will have to be that value which makes the divisor zero.

Now,  x^2-25= 0

Or, x^2= 25

Or, x= +5,-5.

So, for the value +5 and -5, the divisor becomes zero and makes the whole equation undefined.