linear (simultaneous)equations

[Bill_Smalley]

Version: 2004
Operating System: Mac OS X 10.4 (Tiger)
Processor: Power PC

Hi all.

I'm pretty sure that someone once showed me key strokes which solved a set of simultaneous equations written in matrix format without going through the inversion, multiplication routines. That is, you enter the coefficient matrix, the unknown matrix and the right hand side and pressed buttons, then Excel produced the solution vector. Any knowledge?

 

[Carl Witthoft]

Version: 2004
Operating System: Mac OS X 10.4 (Tiger)
Processor: Power PC

Hi all.

I'm pretty sure that someone once showed me key strokes which solved a set of
simultaneous equations written in matrix format without going through the
inversion, multiplication routines. That is, you enter the coefficient
matrix, the unknown matrix and the right hand side and pressed buttons, then
Excel produced the solution vector. Any knowledge?

http://www.dslimited.biz/excel_tutorials/simultaneouslinearequations.html

But keep in mind that Office2008 doesn't have the Solver

From
http://www.ozgrid.com/forum/showthread.php?t=78114
the post:
I can post a trivial example, or you can post your actual system. But if
you have a square coefficient matrix A, a variables matrix X, and a
values matrix B, then the system of linear (i.e., linear in its
coefficients, not necessariliy in its basis functions) equations is

A X = B

Or in Excel-speak,

B = MMULT(A, X)

and the solution is

X = MMULT(MINVERSE(A), B)

If A is non-square (i.e., the system is over-defined), there is a method
to make it square and minimize the residual.