Problem $1\mathrm{.}44$ Evaluate the following integrals:

$($a$){\displaystyle \underset{2}{\overset{6}{}}}(3x^2-2x-1)(x-3)dx.$

$($b$){\displaystyle \underset{0}{\overset{5}{}}}cosx(x-)dx.$

$($c$){\displaystyle \underset{0}{\overset{3}{}}}{x}^3(x+1)dx.$

$($d$){\displaystyle \underset{-}{\overset{}{}}}ln(x+3)(x+2)dx.$