How do I use a graph to solve the system of equations #c+3d=8# and #c=4d−6#?

1 Answer
Amory W.
Sep 13, 2014

The answer is #(2, 2)#. This means that #c=2# and #d=2#.

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You will want your equations in slope-intercept form unless you are familiar with plotting lines from all the different forms. Since the second equation is already in slope-intercept form, it's best to solve for #c# in the first equation.

The first equation is the red line and the second is the blue. The solution is where the red and blue lines intersect. If the lines don't intersect (i.e. parallel), then there is no solution. If the lines are co-linear (i.e. overlapping), then they are dependent.

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