Х1 = а ; х2 = b ; x3 = c
a + 2b + 3c = 4
2a + 6b + 4c = - 6
3a + 10b + 8c = - 8
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- 3a - 10b - 8c = 8
a + 2a - 3a + 2b + 6b - 10b + 3c + 4c - 8c = 4 - 6 + 8
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- 2b - c = 6
2b = - c - 6
a + 2b + 3c = 4
2b = 4 - a - 3c
- c - 6 = 4 - a - 3c
- 10 = - 2c - a
a = 10 - 2c
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2a + 6b + 4c = - 6
2( 10 - 2c ) + 3( - c - 6 ) + 4c = - 6
20 - 4c - 3c - 18 + 4c = - 6
- 3c = - 6 - 2
c = 8/3 = 2 2/3
2b = - 2 2/3 - 6 = - 8 2/3
b = - 26/3 : 2 = - 26/6 = - 4 2/6 = - 4 1/3
a = 10 - 2•8/3 = 10 - 16/3 = 10 - 5 1/3 = 4 2/3
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X1 = 4 2/3
X2 = - 4 1/3
X3 = 2 2/3
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Проверка
4 2/3 + 2•( - 13/3 ) + 3•( 8/3 ) = 4
4 2/3 - ( 26/3 ) + 8 = 4
4 2/3 - 8 ( 2/3 ) + 8 = 4
4 2/3 - ( 2/3 ) = 4
4 = 4