What is 2/5 x - 2 5/12

The answer is - 29/30 x

I'm guessing you mean 2/5 x (-2 5/12), not 2/5x - 2 5/12.

First change the mixed number into improper form: 2 5/12 = 149/12

Now multiply together: 2/5 x 149/12 = 298/60

Lastly, convert into mixed fraction (unless your question states otherwise) : 298/60 = 4 8/60

Your final answer will be: 4 8/60 or 4 4/30 simplified