divisibility - divisors of natural numbers

I have a problem with an exercise.
I have the two following sentences I have to determine if they are true or false.

If $a

If $a

I think the first is true. But I can't understand what's the different when removing the brackets?

Thanks.

EDITED!
I was mistaken copying the questing. Sorry! Now its correct

Answer

The first one is true even if you remove the hypothesis that $a

I also see no difference between the assertions.