the easiest way is definitely to gamble it all and either win or lose everything though it is really risky to be honest
also you should try trading it and you will most probably earn some coins with it though it will be really slow
Gambling is not at all a good suggestion for turning 7 to 17 but it is good for making it from 7 to 2 or 7 to 0 though.
And trading will not earn you profits but will cause a big loss to you if you have no experience about it, and if you have some experience about trading then it can give you great profit and that profit is not slow at all.
But i think gambling best and easier way to make 7 to 17 btc but there are too risky at all If you have proper knowledge about gambling site then you play and make more If you don't have experience then you don't play gambling because you will loose your all coin .