When we say, "a system of linear equations works", what does that really mean?

The linear equations (the system) are productive members of society and are able to hold a steady full time job working 40
hours a week.

The linear equations (the system) share one or more ordered pairs (x,y) when graphed.

The linear equations (the system) have nothing in common.

The linear equations (the system) have the same y-intercept when graphed.