d4y/dx4 - 4 d3y/dx3 - 5 d2y/dx2 + 36 dy/dx - 36y = -8e^x Given that λ^4 - 4λ^3 - 5λ^2 + 36λ - 36 = 0 can be factored to obtain (λ-2)^2 (λ^2 - 9) = 0 find the general solution to this equation I can answer the question no problem BUT where does the -8 on the RHS of the equation go?? If i set y=e^λx i get λ^4 - 4λ^3 - 5λ^2 + 36λ - 36 = -8 ?? so why hasnt he factorised λ^4 - 4λ^3 - 5λ^2 + 36λ - 28 = 0 ?? Totally confused. Thanks for any help.