**Answer:**

15 or -23

**Step-by-step explanation:**

I think you probably already turned this in but in case you haven't:

ST = 19 means that line segment ST is 19 units long. If we know that S is at -4, then T has to be 19 units away from -4, right?

So there's two directions we could go.

Add 19 to -4 to get 15, so T could be at 15. (If there's a line drawn between -4 and 15, it would be 19 units long.)

But the line could go left, towards negative infinity, too. So if we subtract 19 from -4, we'd get -23. T could also be at -23. (If there's a line drawn between -4 and -23, it would also be 19 units long. There's no such thing as a negative length.)

Please mark as Brainliest! :)