Unfortunately, the XPS 15 9575 2-in-1 has soldered RAM - NotebookCheck.net News
Dell XPS 15 review: A pricey premium laptop with a better-than-HD display - CNET
Amazon.com: Dell XPS 15 7590,15.6 4K UHD (3840 X 2160) Touch, 9th Gen Intel Core i7-9750H (12MB Cache, up to 4.5 GHz, 6 Cores), 16GB DDR4-2666MHz RAM, 1TB SSD, NVIDIA GeForce GTX
2021 The Ultimate Dell XPS 15 9500/9510/9520 RAM and SSD Upgrade with step-by-step instructions - YouTube
How to upgrade the RAM in your Dell XPS 15 (9570) | Windows Central
Dell XPS 15 9510 gets a 3.5K OLED touch option along with ray tracing and DLSS support thanks to RTX 3050 and RTX 3050 Ti Laptop GPUs - NotebookCheck.net News