The short answer is: There is no official OTA (Over-The-Air) Lollipop update from Huawei. But thanks to the developer community on forums like XDA-Developers and 4PDA, you can flash a stable custom ROM based on Android 5.1.1 Lollipop.
Huawei did not release a stable, global official build of Android 5.0 for the MediaPad X1 7.0. Consequently, users seeking this update cannot utilize standard OTA mechanisms or official Huawei HiSuite software. The installation of Lollipop requires the adoption of Custom ROMs—typically built from source code such as CyanogenMod 12 or 12.1 (now LineageOS). huawei mediapad x1 70 update lollipop install
: Locate the specific Android 5.1.1 Lollipop / EMUI 3.1 firmware for your model from reputable third-party archives like HardReset.info . The short answer is: There is no official