Question

2) Solve the simultaneous equations in Excel.

x1	x2	x3	x4	x5	x6	RHS
-24	-43.9	-40.4	76.3	87.9	12.8	-77.8
-5.2	-75	44.9	57.9	62.1	7	91.8
13.3	-82.5	-6.3	47.9	-9.7	-8.8	-12
-97.8	0.4	10	3.5	-96.1	-83	86.8
63.3	10.1	46.1	-3.4	-73.7	89.8	-35.1
77.2	99.1	-67.1	-81.9	42.6	82	-20.4

Answer 1

Step 1:

First use MINVERSE function to find the inverse matrix of the coefficient matrix A. Select the range for 6 by 6 rows and colums. Now insert the MINVERSE formula with coefficient matrix range. return keys CTRL + SHIFT + ENTER to get the inverse of the coefficient matrix A

Step 2 Ax=B    => x = A^-1 . B

Now we are going to use MMULT function to find product of matrix A^-1 and B. First select the range where you want your solution vector. For this selected range insert the formula. Return the keys CTRL + SHIFT + ENTER.