Here is another guide on rooting. This guide can also help you root all Android Devices below Jelly Bean.
1) Take your IdeaTab and enable USB debugging.
2) Download Mobogenie from here: www.mobogenie.com/
3) After installing it on your PC, Connect your IdeaPad and select USB storage.
4) Mobogenie will detect and install necessary drivers.
5) Download SRS Root, from here: www.srsroot.com/
6) Click on 'Root using all methods'.
7) Your IdeaPad will reboot 3 times (in some cases 2). On the second last reboot, your device will lag a lot and there wont be sound. Calm and be cool, this is only normal.
8) On the last reboot, you will have gained root access. Update the Superuser installed to the latest version.
The above guide is for Lenovo IdeaPad A2107. However, using SRS Root, you can root almost all devices below Jelly Bean (I tried rooting my Optimus L5 on Jelly Bean 4.1.2 but didnt work out)
Please hit the thanks but if this helped you out!