Free Fall

I'm looking at my physics book right now and the equation they use is: delta y = V(initial)*delta t + 1/2A(delta t)^2 ...the book tells me to convert the equation into the following: Vi = delta y/delta t - 1/2A(delta t) ...its been a while since I have taken a math/physics class...how the hell did they do this?

Subtract 1/2A(delta t)^2 from both sides,

delta y - 1/2A(delta t)^2 = V(initial)*delta t

And then divide both sides with delta t.

delta y/delta t - 1/2A(delta t) = Vi

For the love of god, use TeX, especially if your equations are ambiguous.

>>1
Cant' be done.
>>2,3 Are, of course, black.

Felix survived the free-fall and we also survived the incoming asteroids!
HISTORY HAPPENED TODAY.
http://www.redbullstratos.com/the-team/felix-baumgartner/
http://neo.jpl.nasa.gov/ca/