Ugh, my math is rusty and I can't seem to simplify this as far as I want to... or when I check my math it's wrong.

A + ( 4.9AB / 60 ) = X + ( 4.9XY / 60 )

=

A + ( 4.9AB / 60 ) = X ( 1 + ( 4.9Y / 60 ) )

=

A + ( 4.9AB / 60 )

------------------ = X

( 1 + ( 4.9Y / 60 ) )

And here's where things start to go wrong. Thanks for the help.