Let f(x)=(2x2+3x8)ln(5x+4)\displaystyle {f{{\left({x}\right)}}}={\left(-{2}{x}^{{2}}+{3}{x}-{8}\right)}{\ln{{\left({5}{x}+{4}\right)}}}.

Then f(x)=\displaystyle {f}'{\left({x}\right)}=