oooo matrix problem!!!!!?

Question

in the last line of my 7x8 matrix,[column 7,row 7] i have a zero and i dont know how to get it to a 1...here is my last matrix

[ [1 0 0 0 0 0 1 600]
[0 1 0 0 0 0 -1 -100]
[0 0 1 0 0 0 -1 0 ]
[0 0 0 1 0 0 -2 -600]
[0 0 0 0 1 0 1 600]
[0 0 0 0 0 1 1 600]
[0 0 0 0 0 0 0 -100] ]

i am using a TI-84 plus calculator for this and i used Xrow and row+ and Xrow+

any help would be greatly appreciated!

thank you

Answer 1

You can't get it to a 1.
It looks like you are solving a system of equations.
When you get a row of zeros in the matrix
and a nonzero number at the end of that row
it means your system is inconsistent.
There's no solution to your original system.

Answer 2

I am assuming the rightmost column of your matrix is the right-hand sides of the equations. If there are no errors in what you have done up to this point (this should be double-checked, of course), then you will not be able to remove the zero from the last row. A row of zeros indicates that the associated system of equations does not have a unique solution. In this case, since the right-hand side for that row is nonzero, it indicates that the system of equations has no solution at all (for how can 0 = -100?)

Such matrices are said to be singular. If your matrix row-reduces to a matrix with rows of zeros, then the system does not have a unique solution.