(15C) 3 Equations with 3 Unknowns

[Gamo]

HP-15C already got the Matrix Solver function but

the Setup Process is tedious and time-consuming.

With this little program it help to eliminate most of

the setup process, user only input data for the Rows and Columns.

-----------------------------------------------------------
Procedure: [USER] mode

Initialize press [D] display 3

Input Data press [R/S] on each rows from left to right

Press [E] Input Data [R/S] input data the columns from top to buttom

When done display should shown [ C 3 1 ]

[R/S] display answer for X
[R/S] display answer for Y
[R/S] display answer for Z
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Program: input program in [USER] mode

Quote:LBL D
MATRIX 0
MATRIX 1
3 ENTER
DIM A
R/S
--------------------------------
LBL 1
STO A // Press [STO] [f] [A]
CLx
R/S
GTO 1
--------------------------------
LBL E
3 ENTER 1
DIM B
R/S
STO B // Press [STO] [f] [B]
R/S
STO B // Press [STO] [f] [B]
R/S
STO B // Press [STO] [f] [B]
RESULT C
-------------------------------------
RCL MATRIX B
RCL MATRIX A
÷
R/S
RCL C // Press [RCL] [f] [C]
R/S
RCL C // Press [RCL] [f] [C]
R/S
RCL C // Press [RCL] [f] [C]
R/S
----------------------------------------
PSE
RCL MATRIX A
MATRIX 9
X<>Y
RTN

Example: [USER] mode

4X + 2Y - 2Z = 8
X + Y + Z = 7
2X + 2Y + Z = 12

Press [D] display 3

4 [R/S] 2 [R/S] 2 [CHS] [R/S]
1 [R/S] 1 [R/S] 1 [R/S]
2 [R/S] 2 [R/S] 1 [R/S] display 1

Pres [E] display 1

8 [R/S] 7 [R/S] 12 [R/S] display [ C 3 1 ]

[R/S] display answer for X = 1
[R/S] display answer for Y = 4
[R/S] display answer for Z = 2

For Determinant press [X<>Y] display answer -2


Gamo 3/2024