[Q] Am I even rooted? topic

Hi. I have a Lenovo A7600-F tablet, and I've been trying to root it. I've heard that iRoot is the best way to root this device, so that's what I did. I went ahead and installed the APK, ran it, and clicked root. It said that it has rooted successfully, so I rebooted, and when I enter iRoot again it says I'm not rooted. However, the Superuser app is still there, and cannot be uninstalled. I click root a second time, and the Superuser app disappears. I reboot, and the Superuser app is back again and iRoot still says I'm not rooted. I installed some root apps and this is the output:

iRoot - Not rooted
Superuser - Not rooted
Root Checker Basic - Not rooted
Some other root checker - Rooted
Root Browser - Apparently rooted
Terminal Emulator - Running the command 'su' puts the number 255 before the typing space
Got Root? -
SU Exists: True
Version: 16 com.mgyun.shua.su
Root Obtained: False

I'm confused. Am I rooted? If I'm not, how do I remove the Superuser app?

By the way, when I look in my device's system files, I can see /system/app/irootsu.apk and /system/bin/su.

halp.

-Adam