You can put this solution on YOUR website! You are correct. The answer is . If you aren't sure, try plugging in some numbers. For instance, let , and . So
---->
Now let's say that , and but now we do NOT know the value of "t". So this means that
----> ----> ----> (which was the original value we gave to "t")
This isn't a foolproof way to confirm your answer, but it may help you see what's happening.