Math help needed really confused

Question

Given f(x)=6-x and j(x)=x^2+4, find each of the following:

(f*j)(2)=

(j-f)(x)=

(fj)(x)=

Answer 1

j(x) = x^2 + 4

j(2) = 2^2 +4 = 4+4 = 8

f(x) =6-x

f(8) =6-8 = -2

(foj)(x) = f(j(x)) =-2

(foj)(2) = f(j(2)) = f(8) = 6-8=-2

(j-f)(x) = j(x) - f(x) = x^2 +4 - 6+x = x^2 +x -2

(j-f)(x) = x^2 +x -2

(jf)(x) = j(x)f(x) = (x^2 +4)(6-x) = 6x^2 -x^3 -4x +24

= -x^3 +6x^2 -4x +24