Question 445568
y=3x-7
6x-2y=12 
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Step 1, arrange the 2 eqns in the same order
y=3x-7
3x-y = 7
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6x-2y=12 --> 3x-y = 6
Now it's 
3x-y = 7
3x-y = 6
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If you subtract, you get 0 = 1
That indicates inconsistency, --> no solution.
If you graph them, the lines are parallel.  No intersection, no solution.