I'd chuck that 2nd tube in the fridge and make a starter for the 1st. No sense using $12 of yeast for one batch. If the yeast is within its expiration date, a good starter shouldn't take more than a day or two to be ready to go.
THEN, I would wash the yeast after the batch is done in primary and disperse the cost of that vial of yeast over several more batches, all-the-while having that 2nd vial as backup.
Maybe off-topic a little, but my 0.02 nonetheless.