Answer:
Yes this is a function
Explanation:
The reason is every input only has one output. So what you look for is if there are two arrows coming from the left side and each arrow points to a different number, then that is not a function, because its basically saying if you "plug in" one number you'll get a different number each time. Which is not a function. Each number must have one arrow, and if it has two, it must be pointing to the same number each time for it to be a function.
I hope this helped :)