Ripped jeans, must-have tees, and belted moto jackets seemed like a really good shopping bet five years ago. They were such much-haves that buyout firm Apax Partners acquired Rue21 Inc. and its signature teen-centric take on them, in a deal valued at about $1 billion including debt. That investment, like so many in the retail landscape, hasn’t worked out so well. The retailer, which had more than 1,000 stores scattered in malls across the U.S., filed for bankruptcy in May after anemic sales took a turn for the worse. Another big retail acquisition hasn’t fared well for Apax, either.