Question

Which ordered pair is a solution to the system of equations?

Answer 1

2x - y = -2 . . . (1)
5x - 2y = -7 . . . (2)
From (1), y = 2x + 2 . . . (3)
Putting (3) into (2), gives:
5x - 2(2x + 2) = -7
5x - 4x - 4 = -7
x - 4 = -7
x = -7 + 4 = -3
y = 2(-3) + 2 = -6 + 2 = -4.

Therefore, the required answer is (-3, -4)

Answer 2

2 x - y = - 2 / * ( - 2 )
5 x - 2 y = - 7  
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- 4 x + 2 y = 4
+
  5 x  - 2 y = - 7
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   x = - 3
  - 15 - 2 y = - 7
  - 2 y = - 7 + 15
  - 2 y = 8
  y = 8 : ( - 2 ) ,  y = - 4 
 Answer:  A ( - 3 , - 4 )