1. y(t) =2/7 exp(5t) + 5/7 exp(-2t)
  2. y(t) = -exp(t-pi/2) sin(2t)
  3. y(t) = 3t - 4t ln(t)
  4. y(t) = (a+bt-ln(t)) exp(-2t)
  5. y(t) = 151/1482 cos(16t) + 16/247 cos(3t)
  6. y(t) = a exp(t) + b exp(-t) + c cos(t) + d sin(t) - 3t - t/4 sin(t)