ASUS said that it does accept an 8GB RAM stick, but they said that after they said that it couldn't be updated.  This was ot the only reason taht I think I was talking to an amateur.  
They told me that it would be a 8GB DDR3L 1600 SDRAM.  
The RAM stick that Crucial told me to put in it is an 8GB DDR3L 1866 SODIMM.  
I have learned that a higher frequency doesn't matter because the system will just resort to the lowest frequency anyway, but....
...I'm not sure about the differences between SDRAM and SODIMM.  I think the support person wasn't very clear on these things either.  
Crucial said to update the BIOS and VGA.  I got the BIOS updated, and that didn't improve things.  I downloaded the VGA driver update too, but I'm unfamiliar about how to get it to install through the Linux Peppermint OS.  
Any advice would be great.