# multi-variable equations

1. ## multi-variable equations

Does anyone have any experience or know of a way to solve multi-variable equations using Excel. For instance, I have the following three-equation system and would like to solve for X, Y and Z.

X+Y-5-Z=25
5Z-Y/2+X=-14
Y+2X+5Z=88

The solution to something as simple as this is pretty straighforward, however, I have some much more complicated 3-equation systems I would lke to solve.  Register To Reply

2. Use the matrix/determinant function MDETERM() to solve simultaneous equations:
1. You must write the equations in STANDARD FORM, i.e.,
X1+ Y1 + Z1 = C1
X2+ Y2 + Z2 = C2
X3+ Y3 + Z3 = C3
Put each numeric value in a cell, for your example, using cells A1:D3 the matrix is: ``Please Login or Register  to view this content.``
Copy/paste cells A1:C3 three times, these will be your X, Y & Z determinants.
Next, copy cells D1:D3
Paste these D values over the:
X column of the X determinant,
Y col of the Y det'mt, &
Z col of the Z det'mt, thus: ``Please Login or Register  to view this content.``
Use the function: MDETERM() to calculate four determinants:
The first determinant using =MDETERM(A1:C3) is the determinant D of the matrix and will be the divisor.

Use the MDETERM fn on each of the remaining three arrays and divide the results of each by D ``Please Login or Register  to view this content.``
Therefore:
X = 255/-4.5 = -56.67
Y = -476/-4.5 = 105.78
Z= -86/-4.5 = 19.11  Register To Reply

#### Thread Information

##### Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts

Search Engine Friendly URLs by vBSEO 3.6.0 RC 1