Ugh, I hated that book. It never went into any detail in its “solutions” and the whole thing seemed like a bag of tricks for solving whatever example they were currently showing. Plus I had to deal with the monstrosity that is WileyPLUS.
The chapters are first, second, and higher order were all a bunch of useless tricks. Then they introduce you to series solutions, where it starts to feel useful, and then they hit you on the side of the head with useless transforms.
ODEs are taught the way they are taught out of tradition, a bad tradition.
I was left with feeling that I had only learned yet another trick until I read Churchill & Brown's Complex Variables and Applications.