How to choose RAM for a laptop?

Question

laptops

Good afternoon.
There is an X542UN laptop with Intel(R) Core(TM) i5-7200U CPU The
information about the processor says that the maximum RAM is up to 32. The information on the laptop manufacturer's website says that the maximum is 16.
The information about the processor says that the maximum frequency is 2133, in a laptop with the factory costs 2400.
At the same time, searching the Internet, I came across the same model only on i7 but already with 32GB on board.
Question: How can I find out which RAM in what size and with what frequency can I install?

Answer 1

in general, believe the manufacturer,
but there are so many specifications and submodels that for a particular case, what is indicated on the site may not be true
, another thing is that 32 memory is an expensive laptop and something can easily be cut off from memory in the motherboard, you just have
to study the forums and ask a question there