[madnak]

But I used symbols! I don't see how the subscripts or the deltas are necessary. All three of us wrote out the constants in explaining the basic problem, but we didn't mash them together or anything. I agree that it's problematic to merge two terms together using arithmetic (and then lose them), it's better to use symbols, but that's why I use a, b, and c when I do the algebra portion. And yes, units matter, but not so much in this case.

I really don't see a difference between using a, b, c and using vsubc, vsuba, deltat. Also just saying (t2-t1) instead of delta t, or saying so/therefore instead of (three dots) is clearer for those who don't know what the symbols mean.