1) 2x + 5y = 17
+ 6x – 5y = -9
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8x = 8
divide both sides by 8 :
Answer : x = 1 (one solution)
2) (3x – y = 0) * 4
(4x + 2y = 14) * 3
12x – 4y = 0
- 12x + 6y = 14
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-10y = -14
Divide both sides by -10
Answer : y = 1.4 (one solution)
3) 6x + 5y = 39
- 3x + 5y = 27
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3x = 12
Divide both sides by 3
Answer : x = 4 ( one solution )
4) 4x – 7y = 3
+ x – 7y = -15
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5x = -12
Divide both sides by 5
Answer : x= -2.4 (one solution)