HP HP-28S - Page 112

In this example you'll use EXPAH (expand) and COLcr (collect) to
manipulate the equation. In the next example you'll use FORM (form
algebraic expression)
to manipulate an equation. All commands in the
ALGEBRA menu are described briefly in appendix 0, "Menu Map."
For complete descriptions, refer to "ALGEBRA" in the Reference Man-
ual. In addition, FORM, a powerful algebraic editor, has its own
section "ALGEBRA (FORM)" in the Reference Manual.
Expand both sides of the equation.
EXPAH
To subtract the left side's x-term (2x) from both sides of the equation,
first put the left side's x-term on the stack.
~ 2 0 X I ENTER I r::
3
-:
-----,-, (":"":C=-+-=S:"":")-/-=A""'--=3""""
2: '2*A+2*X=3*S-3*X+C'
1: '2*X'
[BDJI!IIII:JIimIIIlmI£!IIim1DmJ
Then subtract 2x from both sides.
Collect
the equation.
COLcr
Each side is collected independently, and the x-terms cancel on the
left side.
Now you can isolate x in the equation. Specify the variable you want
to isolate.
~X
9: Symbolic Solutions 111