I am tasked with Solving a System by Graphing. My question is, how do you know which value to randomly assign? The problems are 2x+3y=4 and 3x-y=-5. For the last equation, the book assigned -5/3 as the x value. Where or how do you know to assign -5/3 as a value? I thought you randomly assigned a value. I usually do 0, 2 and 4, yet they assigned 0, -5/3 and -2 for the 3x-y=-5 question. How did they know to assign a -2 as the value for x? Thanks much

You can see the problem here:
http://my.jetscreenshot.com/demo/20111220-oewy-54kb

Question

I am tasked with Solving a System by Graphing.  My question is, how do you know which value to randomly assign?  The problems are 2x+3y=4 and 3x-y=-5.  For the last equation, the book assigned -5/3 as the x value. Where or how do you know to assign -5/3 as a value? I thought you randomly assigned a value. I usually do 0, 2 and 4, yet they assigned 0, -5/3 and -2 for the 3x-y=-5 question.  How did they know to assign a -2 as the value for x?  Thanks much

You can see the problem here: 
http://my.jetscreenshot.com/demo/20111220-oewy-54kb

anonymous · Answer

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