Solve

4y17y+15y=0,y(0)=6,y(0)=12.75\displaystyle {4}{y}{''}-{17}{y}'+{15}{y}={0},\quad{y}{\left({0}\right)}={6},\quad{y}'{\left({0}\right)}={12.75}

y(t)\displaystyle {y}{\left({t}\right)} =