What does it mean for a coordinate pair to solve a system of linear equations?

Obviously you have various linear equations all on the same graph... when two of these lines intersect, the point at which they meet is said to 'solve' the equations, ie the x coordinate when put into both equations will make the same answer... so to answer your question, the coordinate pair which solves a system of linear equations is the point at which all the equations intersect... this can be seen easier when all equations are drawn on a graph.