F(x)=x+5/x+7

Question

Describe the values that are not in the domain. 

Answer 1

f(x) = (x+5)/(x+7)

 

In math, division by zero is undefined.  So any value of x that makes the denominator of f(x), (x+7), equal to zero will make f(x) undefined at that point.  Now x + 7 = 0 when x = -7.  So x = -7 is not in the domain of f(x).