Well, it would make the computation a lot easier:
Without the distributive property:
3 ( 30 - 2 ) =
3 ( 28 ) =
84.
I’m going to assume that you don’t know 3 ( 28 ) right off of the top of your head, so you can do:
3 ( 30 ) - 3 ( 2 ) =
90 - 6 =
84.
This way is much easier and less time consuming because you can do this computation in your head.