i bought a new laptop and dell inspiron 14 5415 ryzen 5700U and it only has 512 mb radeon graphics i can't even play a game properly is there anyway to use the ryzen 7 graphics? or increase vram?
The only place to increase your Integrated Graphics vRAM is through BIOS Settings.
Look in BIOS for any settings concerning the IGPU. If there isn't a settings in BIOS to increase or decrease the IGPU vRAM then DELL made it permanent the amount you have.
Besides, Windows will automatically allocate whatever System RAM your IGPU needs to run a game or program. Increasing vRAM on the IGPU might make it run more efficiently and probably a little bit better. But I would look to see if your laptop hardware is able to run your games at high, medium or low settings by going to one of these Can I Run It websites:
NOTE: Also depends on how much System RAM you have installed in the laptop if it is advisable to increase your IGPU vRAM.