ignoring the time value of money
$12.5B purchase
- 3B cash on hand
- 1B tax credits
- 2.4B sale of desktop boxes to Arris
- 2.91B sale to lenovo
==========
3.19B
and google kept patents, etc. Plus there are potentially -- reporting varies -- up to another $.7B/year they kept it of tax offsets I didn't mention, so subtract another $1.4B [1]
It wasn't so much the net ~$3B (piffle!) but approximately doubling headcount with the sort of people who got Moto to where it was before they were bought, and having to manage all that in a direction where a sale for $0.25 on the dollar is considered a success ($0.55 if you count the divested bits). It isn't quite as irrational as buying Nokia, but it's right up there. Moto was a big giant messy falling knife.
[1] http://www.forbes.com/sites/timworstall/2012/12/22/did-motor...