The first number in the progression is the modifier if you have zero ranks. That never happens for body development, but the idea is that you would just get +0 if you have 0 ranks. Same thing is true for power point progressions.

That's different from most skills. The "combined" progression, for skills where you don't have to also purchase the category, is -30*5*3*1.5*0.5. That means if you have 0 ranks, you get -30. As soon as you get at least one rank, that -30 goes away and you get +5 for that first rank.

We did not keep this concept for RMU, but you could express RMU's progression for all skills as -25*5*3*2*1, or as -25*6*4*3*1 for your professional skills.