Hi;
one of the simplest way would be creating the variables ´x´ and ´y´ then attributing them the values you want to. Consider this:
[x^2+y x^2-2y] [ENTER]
2 'x' [STO]
1 'y' [STO]
[->NUM]
Alternatively you can store the initial expression in a separate variable, say 'EQ1', with the following sequence:
[x^2+y x^2-2y] 'EQ1' [STO]
2 'x' [STO]
1 'y' [STO]
'EQ1' [->NUM]
This way, you could attribute x and y other values, say 3 and 4, like this:
3 'x' [STO]
4 'y' [STO]
'EQ1' [->NUM]
There are other ways, for sure. This is one of them, though.
Cheers.
Luiz (Brazil)
(PS: there may be errors, I have no calculator at hands, now...)
Edited: 18 Apr 2007, 8:10 p.m.