No matter how much you support Arsenal, if you bet your money on this club you will only risk losing money. Indeed, we don't know what will happen in the last match, but I am very sure that Man City will win the league again this season because they failed. in the UCL then you will risk everything in the EPL and will not waste any opportunities, WestHam is not a difficult club for Man City to win the last match, if you show your support for Arsenal by betting on this club be prepared to accept disappointment
Any bet comes with a risk of losing money. But yeah, betting on Arsenal to win the league at this stage means you're most likely to lose.
Then again, the odds of x10.00 are quite attractive to bet some pocket change on it, a small enough amount that you won't feel much difference if it's gone.
Man City is a huge favourite, but, looking from a slightly different angle, and assuming West Ham will care about winning at all (just for the glory), it might not be as easy game as many expect it to bee.
First of all, West Ham know how desperate Man City is for the 3 points, so they'll probably start very defensively and will be focussed on just stealing time. As each passing minute of a goalless game will make the City more stressed and desperate, the risk of them making mistakes or overcommitting to attack will increase, potentially opening situations for counterstrikes for West Ham.
Anyhow, I think the odds for the City to win the game or the league are so low that it's not worth it. From a purely gambling perspective, I think it makes more sense to make a small bet on them not winning. But I wish they succeed, so won't be doing that.