Solve the Cauchy-Euler equation t2y10ty+28y=0\displaystyle {t}^{{2}}{y}{''}-{10}{t}{y}'+{28}{y}={0} with initial conditions y(1)=2,y(1)=7\displaystyle {y}{\left({1}\right)}=-{2},{y}'{\left({1}\right)}={7}.

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