Answer: The answer has one solution:
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 → x = 1 ; y = -4 ; or, write as: [1, -4].
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Explanation:
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Given:
 y = - 1x – 3
 y = -7x + 3 ;
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 -1x – 3 = -7x + 3 ; Solve for "x" ;
Add: " +1x" ; and add " +3 " ; to Each Side of the equation:
Subtract " 1x " ; and Subtract " 1 " ; from Each Side of the equation:
 -1x + 1x – 3 + 3 = -7x + 1x + 3 + 3 ;
 to get: 
 0 = -6x + 6 
 ↔ -6x + 6 = 0 ; 
Now, subtract " 6 " from Each Side of the equation:
 -6x + 6 – 6 = 0 – 6 ; 
 to get: 
 -6x = -6 ; 
Now, divide Each Side of the equation by " -6 "; 
 to isolate "x" on one side of the equation; 
 & to solve for "x" ; 
 -6x /-6 = -6/-6 ; 
 to get: 
 x = 1 .
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Now, let us solve for "y" ; 
We are given: 
 y = -x – 3 ;
Substitute our solved value for "x" ; which is: " 1 " ; for " x " ; into this given equation; to obtain the value for " y " :
 y = -x – 3 ;
 = -1 – 3 
  y = - 4 .
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Let us check our answers by plugging the values for "x" and "y" ;
 " 1 " ; and " -4 "; respectively); into the second given equation; to see if these values for " x " and " y" ; hold true:
Given: y = - 7x + 3 ;
 → -4 =? -7(1) + 3 ?? ;
 → -4 =? -7 + 3 ?? ;
 → - 4 =? -4 ?? ; 
 → Yes!
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The answer has one solution:
 → x = 1 ;  y = - 4 ; or, write as:  [1, -4 ].
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Hope this is helpful! Best wishes!
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