I've just joined and wanted to contribute a bit myself so here are 3 puzzles my friend made to test me, first two I've solved but third one stomped me, see if you can solve it yourself!
First one -
Describe the relation between X (left number) and Y (right number):
1,1 = 0
1,3 = -8
1,6 = -35
1,28 = -783
2,2 = ?
Good job if you solved it but it's going to get harder
Second one -
Again same rules as the first one, however this time there is one parameter involved in the equation that describes the relation:
3,6 = 21
4,14 = 38
7,15 = 78
2,23 = 31
1,7 = ?
Okay this one was harder in my opinion, good job if you solved it! Next one is ALOT harder in my opinion but then again i know there are some brilliant folks here
Third one -
Same rules as the first two however this time there are two parameters involved in the equation:
1,14 = 4
3,16 = 192
3,26 = 132
7,10 = 1428
1,1 = ?
Good luck!