Answer:
All real numbers
Step-by-step explanation:
Given the two functions
a(x) = 3x + 1 and b(x) = x - 4
The composition (boa)(x) is the same as:
b(a(x))= (a(x)) - 4 = (3x + 1) - 4 = 3x + 1 - 4 = 3x - 3
This is still a linear function and therefore its domain is all real numbers (we can find a y value given any real number x)