Question

If a(x) = 3x + 1 and (x)= x-4, what is the domain of (boa)(x)?

Answer 1

I am assuming you meant to write b(x) = x-4.

$(b \circ a)(x)=b(a(x))=b(3x+1)=(3x+1)-4=\boxed{3x-3}$

Since this is a linear function, the domain is all real numbers.