Question

For which values of x is the expression undefined?
x2 – 49
x2 – 16

Answer 1

You meant to say x^2 - 49 and the second binomial is x^2 - 16.

x^2 - 49 = (x - 7) (x + 7).

Set each factor to 0 and solve for x individually.

x - 7 = 0

x = 7

x + 7 = 0

x = -7

Do the same for x^2 - 16.

Here is the set up:

x^2 - 16 = (x - 4) (x + 4).

Take it from here.