Like Jen said, Saxon is good at walking people through things. If you DO homeschool, you may be surprised at how much Luke can do on his own, with the help of a good step-by-step guide.
The other thing that people tend to forget is that there's nothing that says THEY can't learn subjects in order to teach them. The learning function doesn't get switched off when we graduate from high school or college...and even someone with an advanced degree has to do some studying to teach a subject. I don't remember half of my Algebra II, but I did some tutoring of a friend a few years ago and with the help of a Saxon book was able to relearn it in order to explain it to her.
That might work with Luke. It would never have worked with Jr.
And, no, I gave up math class a long time ago and have never looked back.