The following video demonstrates that it is possible to play Dota 2 on a laptop with a Pentium N3700, but performance is relatively low at 1366x768 resolution where the FPS is mostly at around 25 FPS, but it does dip down to around 15 FPS.
https://www.youtube.com/watch?v=5WLcfl0ODTA
I recommend the following Acer Aspire E 15 E5-575-33BM for $350. It has a Core i3-7100u CPU, Intel HD 620 graphics core and 1080p screen. I can max out LoL and it will be fine for Dota 2.
https://www.amazon.com/Acer-E5-575-33BM-15-6-Inch-Processor-Generation/dp/B01K1IO3QW/ref=sr_1_1?s=pc&ie=UTF8&qid=1484346003&sr=1-1&keywords=i3-7100u.
The following video demonstrates Dota 2 running on a similar laptop with the i3-7100u, but it only has a 1366x768...