Is this the dell inspiron you are talking about? http://www.dell.com/my/p/inspiron-14-7437/pd

If yes, it is only a intel hd graphic, which provides very basic graphic processing.

If you want to game/ photoshop/ movie editing, then Y50 should be your choice without even thinking.

If it's just normal surfing web, then the dell inspiron might be better as the intel hd graphic is not battery hungry at all compare to Y50. Although, Y50 will have intel hd graphics in it as well if I'm not mistaken as my old y580 have both intel hd and nvidia gpu.

Okay, then its gtx 850m vs gtx 860m.

2 way to determine which is better.

1st, look at the number, bigger is obviously better.

2nd, look at gpu benchmark website/ google.

Okay, on a serious note. Both laptop are good, it all depends on which you prefer. dell have the 14" ips display which imo might be better than the display of the 3.5k version of y50 which many people dislike. Y50 on the other hand have the better gtx860m 4gb gddr5 while dell only have gtx850m ddr3.