Question 251127
elimination
3x - 4y = 12  
4x - 4y = 12
-------------- Subtract
-x = 0
x = 0
y = -3
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To graph, find 2 points for each eqn and draw a straight line thru them.
3x + 4y = 12
x...y
0...3 --> (0,3)
4...0 --> (4,0)
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Do the same for the other eqn.  Where they intersect is the solution.