Consider the indefinite integral ${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x+4}{(4x+5{)}^2}dx.$

The substitution $u=4x+5$ transforms the integral into:

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}du$

$($This answer must be a function of $u.)$

Note: You are not asked to evaluate the integral.