SOLUTION: Solve for x and y using addition or substitution. 2x -3y = 4 2x + y = -4

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Question 428601: Solve for x and y using addition or substitution.
2x -3y = 4
2x + y = -4
Answer by algebrahouse.com(1659) About Me  (Show Source):
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Solve for x and y using addition or substitution.

2x - 3y = 4 ------> -2x + 3y = -4 {multiplied top equation by -1}
2x + y = -4 -------> 2x + y = -4 {bottom equation stays the same}
4y = -8 {added the two equations together}
y = -2 {divided both sides by 4}

2x + y = -4 {bottom equation}
2x - 2 = -4 {substituted -2, in for y, into bottom equation}
2x = -2 {added 2 to both sides}
x = -1 {divided both sides by 2}

x = -1 and y = -2
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