Question

Find a number b such that f∘g=g∘f, where f(x)=3x+4 and g(x)=bx−4. b=

Answer 1

f(g) = 3g+4 = 3(bx-4)+4 = 3bx-8

g(f) = bf-4 = b(3x+4)-4 = 3bx+4b-4
Clearly, b = -1