Respostas

2013-09-19T16:09:13-03:00
{X+3Y-Z=2
{2X+4Y+Z=7
{3X+9Y-3Z=8


x = 2 - 3y + z
2(2 - 3y + 2) + 4y + z = 7
4 - 6y + 2z + 4y + z = 7
-2y +3z = 7 - 4
-2y + 3z = 3
3z = 3 +2y
z = 3/3 + 2y/3
z = 1 + 2y/3

3(2 - 3y + 1 + 2y/3) + 9y - 3(1 + 2y/3) = 8
6 -9y +3 + 6y/9 + 9y - 3 + 6y/9 = 8
2/3y + 2/3y = 4/3y = 8 - 6
y = 2/4/3 = 2*3/4 = 3/2
y = 3/2

z= 1 + 2/3 * 3/2
z = 1 + 6/6
z = 2

x = 2 - 3*3/2 + 2
x = 2 - 9/2 + 2
x= -1/2
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