2x + 5y = 14 / * ( - 3 )
6x + 7y = 10
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- 6x - 15y = - 42
6x + 7y = 10
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- 8y = - 32
___ _____
-8 -8
_______________
y = 4
2x + 5*4 = 14
2x + 20 = 14
- 20 - 20
_________________
2x = -6
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2 2
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x = - 3