Find the most general antiderivative:

$($a$)$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{5x^4-3\sqrt[\phantom{2}]{x}}{4x}dx$

$($b$)$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}(2cs{c}^{2}x-sinx)dx$

$($c$)$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{(lnt{)}^2}{t}dt$