If you has CWM or TWRP flash this Patch Root v31 Blu life play l100i e l100a.
If you not has custom recoveries, try using VRoot....or similar application...
Sent from my LIFE PLAY X KK using XDA Free mobile app
thanks +lopestom, should I flash both files? and what if I don't have CWM? how do I install it? thanks for your help