Sadly, Laptops, especially dell laptops, are un-modifiable when in relation to GPUs. Currently you are using the integrated Intel GPU built into the laptop.
From what I know of, laptops aren't very friendly with upgrades, and the best I have seen from laptops is ram swap outs.
You would have to either have to open the laptop yourself and see if anything looks like it might move, if you're still not sure, check the Asus website for more information...
So my question about the Lenovo's G50-45 computer, is it possible to change the video card? and if so, what card? I plan to switch it out with the MSI GeForce 4GB 256-Bit GDDR5 Graphics Card (GTX 970 GAMING 4G)
Ask for more info if needed