Chapter 9 - Section 9.1 - The Algebra of Functions; Composite Functions - Exercise Set - Page 540: 19

$f(g(x))=-8x^3-2x-2$ $g(f(x))=-2x^3-2x+4$

f of g(x) means $f(g(x))$ $g(x)$ is given as $-2x$ Therefore $f(g(x))=(-2x)^3+(-2x)-2=-8x^3-2x-2$ g of f(x) means $g(f(x))$ $f(x)$ is given as $x^3+x-2$ Therefore $g(f(x))=-2(x^3+x-2)=-2x^3-2x+4$