## Intermediate Algebra (6th Edition)

$a^2+2ah+h^2-3a-3h$
Replacing $x$ with $a+h$ in the given function, $f(x)=x^2-3x$, then $f(a+h)$ is equal to \begin{array}{l} (a+h)^2-3(a+h) \\\\= a^2+2ah+h^2-3a-3h .\end{array}