3Х - 2Y = 1
2Y = 3X - 1
Y = 1,5X - 0,5
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X + 3Y = - 2
X + 3 * ( 1,5X - 0,5) = - 2
X + 4,5X - 1,5 = - 2
5,5X = - 0,5
X = ( - 1/2) : 11/2 = ( - 1/11 )
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Y = 1,5X - 0,5
Y = 3/2 * ( - 1/11) - 1/2 = ( - 3/22) - 11/22 = ( - 14/22) = ( - 7/11 )
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Ответ Х = ( - 1/11) ; Y = ( - 7/11 )
3а - 5(4а-3b)+2(3b-a - 1)= 21(b-a)-2