Can I use an SRAM 10spd Mech on a 3x9 system?

[Peewee1]

Hello fellow hubbers.

 

Been trying to do some research but not getting a clear answer.

 

I have a full SRAM X9 9speed system on my bike. I have a X9 10speed Rear mech I want to replace the 9 speed mech with. Can this be done? Apparently the pull ratios are slightly different.