ice007

Hi All, I really need to understand laplace transform as i have an assignment on it. Its really confusing for me can anyone assist me on the following questions. Please help me to understand s^4 – 6s^3 + 18s^2 / 3s^6 ac + bs / s^2 + a^2 s + 5 / s2 - 6s + 25 and a differential equation using laplace tranform f'(t) + f(t) = e^-t, f(0) = 0 Thank you very much