two linear equations that represent the same line will be scalar multiples of one another ... just eliminate one of them.
I just need to clarify this. If I have too many equations (lets say 5 equations and 4 unknowns), when we say there is collinearity that means that 2 of the equations are telling us the same thing correct? And to solve this we need to try and rewrite these collinear equations as one equation?
Thanks very much for the help,
There is another situtation that arises . . . and it's harder to see.
If one equation is a linear combination of the other two,
. . the system is dependent; one equation can be dropped.
To test for dependence:
Multiply equation  by , multiply equation  by , and add.
If this sum can equal equation  for some values of and ,
. . the system is dependent.