2x + 1y + 2z = -12
4x + 3y - 3z = -2
6x + 5y - 8z = 9
2007-03-27 02:01:00 · 3 answers · asked by Rocstarr 2 in Science & Mathematics ➔ Mathematics
#1: 2x + y + 2z = -12
#2: 4x + 3y - 3x = -2
#3: 6x + 5y - 8z = 9
Multiply #1 by 3, and #2 by 2, and add them together:
#1: 6x + 3y + 6z = -36
#2: 8x + 6y - 6z = -4
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14x + 9y = -40
Go back to the beginning...
Multiply #1 by 4 and add it to #3:
#1: 8x + 4y + 8z = -48
#3: 6x + 5y - 8z = 9
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14x + 9y = -39
Now we have two equations:
14x + 9y = -40
14x + 9y = -39
This system has no solution. You can't have identical equations equal to two different numbers.
2007-03-27 02:07:58 · answer #1 · answered by Mathematica 7 · 0⤊ 0⤋
Easier than determinates is to set up a matrix equation to solve the equations
2007-03-27 09:13:43 · answer #2 · answered by Ray 5 · 0⤊ 0⤋
Use determinants i.e. Cramer's rule.
This will make it very simple.
If not, then you have to first eliminate z from 2 eqns, and then solve them simultaneously to get x & y and then substitute to find z. This will be tiresome.
2007-03-27 09:09:39 · answer #3 · answered by nayanmange 4 · 0⤊ 0⤋