Matrix workings (systems of linear equations)

[Yendall]

For full marks, do you have to show the consistency or dependency through graphing the two sets of linear equations? Or will you still obtain full marks by proving that the determinant of a matrix is not equal to 0, and then solving the sets?

Also, if equations are inconsistant or dependant, does that mean they have a unique solution?

Thanks.

[paulsterio]

as long as det =/= 0, you will have unique solutions

[Yendall]

as long as det =/= 0, you will have unique solutions

And as long as you prove that through workings you would obtain full marks? I know it's a stupid question, but my teacher insists on showing complete working. If i just wrote on the side that I used Det|A| to find that A =/= 0, and then solved the equations that would be enough?

[paulsterio]

It would be enough to show that a solution exists, yes.

[Yendall]

It would be enough to show that a solution exists, yes.

Okay sweet, thanks for that.