In each of Problems $7$ through $14$ verify that each given function is a solution of the differential equation.

$9.t{y}^{\text{'}}-y=t^2$;$,y=3t{t}^2$

$11.2t^2{y}^{\text{'}\text{'}}3t{y}^{\text{'}}-y=0,t>0$;$,y_1(t)=t^{\frac{1}{2}},lo{s}_s(t)=t^{-1}$

$13.y^{\text{'}}-2ty=$;$,y=e^{t^2}{\displaystyle \underset{0}{\overset{1}{}}}{e}^{-s^2}ds{e}^{t^2}{y}^{\text{'}\text{'}}y=sect,0$

Just #$9,11,$ and $13$ please!