Just subtract horizontal 9-5 is 4 and keep the denominator the same
So 5/14 is the answer
The phrasing of the question implies there are multiple choices. Is this true?
f(x) = 7x - 1
-2 = 7x - 1
-2 + 1 = 7x
-1 = 7x
x = -1/7
0 = 7x - 1
1 = 7x
x = 1/7
4 = 7x - 1
4 + 1 = 7x
5 = 7x
x = 5/7
8 = 7x - 1
8 + 1 = 7x
9 = 7x
x = 9/7
So the domain is
Domain = {-1/7, 1/7, 5/7, 9/7}
0 because you can divide them ie 0 is divisible with 5 and 10