( Х + 14 ) / 6 - ( Х - 12 ) / 8 = 3
Общий знаменатель 24
4( Х + 14 ) - 3( Х - 12 ) = 3 • 24
4х + 56 - 3х + 36 = 72
Х = 72 - 92
Х = - 20
X + 5y = 7
3x + 2y = - 5
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x = 7 - 5y
3 * ( 7-5y) + 2y = - 5
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3 * ( 7-5y) + 2y = - 5
21 - 15y + 2y = -5
-13y = -5-21
-13y = -26
y = 2
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x = 7 - 5* 2 = 7 - 10 = - 3
Ответ: (- 3 ; 2 )