Question 107573
Lets name the equation
2x-y=4    ----------- 1
6x+3y=-18 ----------- 2
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From equation 1
y=2x-4    ----------- 3
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Subsititue equation 3 into equation 2
6x+3(2x-4)=-18
6x+6x-12=-18
12x=-6
  x={{{-1/2}}}
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Subsititue x into equation 3
y={{{2(-1/2)-4}}}
 =-1-4
 =-5
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Good Luck, By: Mathnoob