Verify that the function is a sol'n of the given differential equation:

t*dy/dt - y = t^2, y = 3t + t^2

So I worked with y = 3t + t^2

y' = 3 + 2t

y'' = 2

Then, t*dy/dt - (3t + t^2) = t^2 .. so if it did work, that means t*dy/dt = 3t, but I don't seen how.