I have an old TI-89 calculator and it has the ability to use a variable in a formula and then assign it at the end in one line:
But I never could quite figure out how to use multiple variables at once without storing them ahead of time:
5->x 12->y x+y 17
But I want to do this on one line without having to save the variables. The solution is to use the "and" keyword.
x+y|x=5 and y=12 17
The most annoying thing about this though is the only way I know of to add the "and" keyword is to look it up in the Catalog menu.