Linear systems of equation should be solved using Algebrator. If necessary, please use one of the following links to obtain a free trial of the program:

Windows: http://www.softmath.com/tr/alg51win-tr-en.exe

Mac: http://www.softmath.com/tr/alg51mac-tr-en.dmg

The software contains many instructional flash demos, available through the drop-down menu "Help->Tutors". An appropriate flash demo for this type of problem is "Solving systems of equations". You may enter each equation on a line of its own and the software will solve this "system of two equations in two unknowns". To control the method by which the system is solved, use the drop-down menu "Solution->Settings", where both substitution and elimination are shown as options. If you wish to solve the system graphically you could simply graph the equations (enter them the same way but press "Graph All" instead) and then identify the point where the lines intersect, if they do intersect.

It is important to understand that anytime you are solving a system of equations you are answering the basic question "Do the graphs of these equations touch?". They may touch in one point (one solution), no points (no solutions) or an infinite number of points (i.e. the equations define the same line). For this reason, it is always helpful to press "Graph All" after the solution as this allows you to see a graph of the equations and better understand the solution you obtained.

If solving the system graphically, one may obtain estimates for the point of intersection [if such a point exists]. To do so, simply use a drag of the mouse [with the left button held down] over the point of intersection and zoom in on that point by repeating the process until the zooming has maxed out or you are confident that you can place the cursor over the point of intersection. By placing the cursor over the point of intersection and pressing the right button of the mouse, a pop-up will indicate the numeric values for x and y at that point.

When solving systems of linear equations numerically, the software will provide the answer for each variable. If you wish to represent the answer as an ordered pair, then simply rewrite it as such. You may be given a system in which the variables are "b" and "c" and asked to report the answer as (c,b) - the software will report the answers one variable per line and you may then rewrite the ordered pair using the correct variable in the correct position. We are not able to assume that "x" and "y" will always be the variable pairs, nor are we able to assume that all answers should be reported as (x,y) because there are many ways to define a coordinate system, therefore an ordered pair is not used by the software in reporting the answer.