It sounds like your microphone is picking up the voice of the other person on the call with you. The Lenovo IdeaPad 3 17 model number 81W2004AUS, does ship with a Dual Array Microphone that can pick up your voice from any angle and at greater distance from the microphone than standard microphones. Here are some tips for reducing echo for other callers: https://support.microsoft.com/en-us/office/your-audio-device-may-cause-an-echo-124e3b6c-6d01-4db2-94a3-75c0ecc289c3

No. The keyboard on the Duet Chromebook is removable.

That will depend on the requirements and compatibility of the software you want to run. The Lenovo IdeaPad 3 14 laptop, model number 81W0009DUS, ships with Windows 10 S-Mode 64-bit Operating System. Windows 10 S-Mode provides added security by only allowing APPs available ( and therefore certified by Microsoft) at the Microsoft Store. If you don't need the added security or you need to install APPs not available at the Microsoft Store, you can switch to standard Windows 10 Home 64-bit Operating System, at no additional cost. We recommend you check with the software publisher's web site of the software you want to use, for their compatibility with Windows 10 S-Mode 64-bit operating system and the minimum/recommended hardware requirements (Is a Graphics card required, the processor speed and the minimum required system RAM and the minimum available hard drive space) to run their program, then compare those requirements to this system's configuration.

No. The maximum RAM the manufacturer specification lists for the Lenovo IdeaPad 3 15 Laptop, model number 81WE00KVUS, is 12GB. There is 4GB soldered to the motherboard and another 4GB in the one RAM memory slot within this configuration. The 4GB RAM memory stick can be replaced with an 8GB stick for a system maximum RAM of 12GB. Please keep in mind, this model is not user upgradable. A certified technician must do all of the work, so as to not void the warranty. We recommend you consult with your certified technician about your RAM upgrade options.