Question 186643
 x+2y=-9
4x+2y=6
.
Multiply both sides of top equation by -1:
-x-2y=9
4x+2y=6
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Now, add the two equation together:
-x-2y=9
4x+2y=6
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3x   =18
x = 6 (solution for x)
.
Substitute the above back into the original top equation and solve for y:
 x+2y=-9
 6+2y=-9
   2y=-15
    y=-15/2 (solution for y)