Chosen Solution

I want to upgrade my laptop with an extra 4 GB RAM. I have ACER-V3-574G model laptop with 4GB DDR3L 8400 RAM with clock speed 1600 MHz (part number: ACR16D3LS1KNG/4G). If I add DDR3L 12800 with clock speed 1600 MHz, will it be compatible with the previous existed RAM? Please help.

Looks like it will work. This model seems to take mixed RAM ()which frankly, I would not do). https://www.crucial.com/usa/en/compatibl