x - 3y - 3z = 9
5x - 3y + 3z = -3
--------------------add
6x - 6y = 6
x - 3y - 3z = 9.....multiply by -4
-4x + 2y - 4z = 4..multiply by 3
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-4x + 12y + 12z = -36 (result of multiplying by -4)
-12x + 6y - 12z = 12 (result of multiplying by 3)
-----------------add
-16x + 18y = - 24
6x - 6y = 6.....multiply by 3
-16x + 18y = -24
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18x - 18y = 18 (result of multiplying by 3)
-16x + 18y = -24
--------------------add
2x = - 6
x = -6/2
x = -3
6x - 6y = 6
6(-3) - 6y = 6
-18 - 6y = 6
-6y = 6 + 18
-6y = 24
y = -24/6
y = -4
x - 3y - 3z = 9
-3 - 3(-4) - 3z = 9
-3 + 12 - 3z = 9
9 - 3z = 9
-3z = 9 - 9
-3z = 0
z = 0
so ur solution is (-3,-4,0)