what is the domain of f(x)= x-7/x-8

Question

I need this answered! If you could also explain how you got the answer would be helpful also 

 

Answer 1

At x = 8, the denominator of f(x) becomes 0 and division by zero is undefined.  Hence f(x) is undefined at x=8.  The domain of f(x) is all values of x except x=8.  In interval notation:

 

(-∞,8)U(8,∞)