## College Algebra (10th Edition)

$g(x) - f(x)$ or $(g-f)$
Notice that $(x+1)$, which is equal to function $f$, is subtracted to $x^3$, which is function $g$. Thus, $g(x)-f(x)=x^3-(x+1)$ Therefore, the missing expression in the given statement is: $g(x) - f(x)$ or $g-f$.