Because background programs also eat memory, some applications cannot be closed because of system services. You can try the following methods:

1, just press and hold the home button on the desktop to clean up, and one-click cleaning can help you clean up the memory.

2, the best way to clean up the memory is to restart the phone, other settings, other advanced settings, developer options, system memory optimization level are all helpful.

3. Format and remember to back up.