help with math problem! Matrices?

Question

I have to figure out this problem by using the Gauss - Jordan elimination method (matices)...but when i do it, it's not adding up with the answer in my book. Here's the problem :

x +2y - 3z = 1
2x - y +2z = -8
3x - y -4z =3

The answer in my book is (-1,2, -2). Please help!

Answer 1

Check it again; it seems the answer in your book is wrong.

(-1,2, -2) is not a solution of

x +2y - 3z = 1
2x - y +2z = -8
3x - y -4z =3
-

Answer 2

Matrix multiplication is in simple terms taking the dot made from row i of matrix A with column j of matrix B, to kind the ij get admission to of the matrix (AB). think of "row dot column". The order of matrix is (rows)x(columns). If there are 3 rows in A and 3 columns in B, then there could be 3 rows and 3 columns in (AB) for the above dot product to artwork out. additionally, the dimensions of each and every row of A (the kind of columns of A) and the top of each and every row of B (the kind of rows of B) could be equivalent for the dot product to be defined. In all, right this is the rule governing matrix multiplication orders: (nxm)x(mxp) = (nxp)