(12C Platinum) Two Linear Equations in Two Unknowns
11-28-2018, 08:15 AM
Post: #1
 Gamo Senior Member Posts: 468 Joined: Dec 2016
(12C Platinum) Two Linear Equations in Two Unknowns
Here is my first attempt to program in ALG mode.

This program solve for Simultaneous Equation in Two Unknowns.

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Formula using Cramer's Rule

Equations:

Ax + By = e
Cx + Dy = f

If AD - BC = 0 there is No Solution.

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Procedure:

Input: A [R/S] B [R/S] e [R/S] C [R/S] D [R/S] f [R/S] [R/S]
Display: X [R/S] Y

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Example:

2X - Y = 15
X + 2Y = 30

2 [R/S] 1 [CHS] [R/S] 15 [R/S]
1 [R/S] 2 [R/S] 30 [R/S] [R/S] display 12 [R/S] 9

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X + Y = -1
2X + 2Y = -2

1 [R/S] 1 [R/S] 1 [CHS] [R/S]
2 [R/S] 2 [R/S] 2 [CHS] [R/S] [R/S] Display 0.000000000 briefly then 0.00

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Program: Linear Equation in Two Unknowns (ALG Mode)
Code:
 001 STO 1 002 R/S 003 STO 2 004 R/S 005 STO 3 006 R/S 007 STO 4 008 R/S 009 STO 5 010 R/S 011 STO 6 012 R/S ------------------------- 013  ( 014 RCL 3 015  x 016 RCL 5 017  ) 018  - 019  ( 020 RCL 2 021  x 022 RCL 6 023  ) 024  = 025 STO 8 --------------------------- 026  ( 027 RCL 1 028  x 029 RCL 5 030  ) 031  - 032  ( 033 RCL 2 034  x 035 RCL 4 036  ) 037  = 038 STO 0 ------------------------------- 039 X=0 040 GTO 067 041 RCL 8 042  ÷ 043 RCL 0 044  = 045 STO 7 046  ( 047 RCL 1 048  x 049 RCL 6 050  ) 051  - 052  ( 053 RCL 3 054  x 055 RCL 4 056  ) 057  = 058  ÷ 059 RCL 0 060  = 061 X<>Y 062 RCL 7 063 R/S 064 Rv 065 Rv 066 GTO 000 ------------------------------ 067  0 068 FIX 9 069 PSE 070 FIX 2

Gamo
01-16-2019, 04:46 AM
Post: #2
 Gamo Senior Member Posts: 468 Joined: Dec 2016
RE: (12C Platinum) Two Linear Equations in Two Unknowns
ALG Mode Program Version II

Procedure:
Same as above except when result is no solution
Display "Error 0"

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Program: ALG Mode
Code:
 STO 0 R/S STO 1 R/S STO 2 R/S STO 3 R/S STO 4 R/S STO 5   RCL 0 x RCL 4 - (RCL 3 x RCL 1) = STO 6 RCL 2 x RCL 4 - (RCL 1 x RCL 5) ÷ RCL 6 = R/S RCL 0 x RCL 5 - (RCL 3 x RCL 2) ÷ RCL 6 =

Gamo
01-16-2019, 01:36 PM (This post was last modified: 01-16-2019 02:01 PM by Albert Chan.)
Post: #3
 Albert Chan Senior Member Posts: 622 Joined: Jul 2018
RE: (12C Platinum) Two Linear Equations in Two Unknowns
(11-28-2018 08:15 AM)Gamo Wrote:  Example:

X + Y = -1
2X + 2Y = -2