Now the three numbers I managed to get are 25, 31 and 37 (as I assumed it meant the output of both of these sequences needs to be the same as well as being in between 20 and 40). For example 2x18+1= 37 as does 3x12+1= 37
if you multiply 'y' by -5 it turns into -5y. Therefore when you add -5y and 5y together, you get 0y which is what you want when eliminating the y-term.
