HP -28S Manual page 115

Display the first row of manipulations for
+.
[ NEXT
I .-----------------,
««A*X);(A*B))+(2*X))=
C)
. . KDlllmlmaI . . . .
The manipulations that appear when you press [
NEXT
I
are specific to
the function or variable indicated by the cursor; these manipulations
are specific to
+.
Commute the arguments to
+,
using
++
(commute).
Return to the main FORM menu.
[ENTER
I
Step 2: Associate
ax and 2x.
Move the cursor to the second
+
[ot] [ot]
[ot]
[
..
]
Here you want to act on the sub expression
CCCAtB)+CAtX»+C2tX»
to associate the terms CAt;.-;) and C 2 t X) in a single subexpression.
Display the first row of manipulations for
+ .
I
NEXT
I
.--------------------------~
These are the same manipulations as before because the cursor again
indicated an additive subexpression.
114 9: Symbolic Solutions