Problem to solve
Solve \[-x+3y+2z=5\], \[-3x-2y+z=-4\], \[x-y+z=3\]
Solution
STEP 1
Solve the following system:
{-x + 3 y + 2 z = 5
-3 x - 2 y + z = -4
x - y + z = 3
STEP 2
Express the system in matrix form:
(-1 | 3 | 2
-3 | -2 | 1
1 | -1 | 1)(x
y
z) = (5
-4
3)
STEP 3
Write the system in augmented matrix form and use Gaussian elimination:
(-1 | 3 | 2 | 5
-3 | -2 | 1 | -4
1 | -1 | 1 | 3)
STEP 4
Swap row 1 with row 2:
(-3 | -2 | 1 | -4
-1 | 3 | 2 | 5
1 | -1 | 1 | 3)
STEP 5
Subtract 1/3 × (row 1) from row 2:
(-3 | -2 | 1 | -4
0 | 11/3 | 5/3 | 19/3
1 | -1 | 1 | 3)
STEP 6
Multiply row 2 by 3:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
1 | -1 | 1 | 3)
STEP 7
Add 1/3 × (row 1) to row 3:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
0 | -5/3 | 4/3 | 5/3)
STEP 8
Multiply row 3 by 3:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
0 | -5 | 4 | 5)
STEP 9
Add 5/11 × (row 2) to row 3:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
0 | 0 | 69/11 | 150/11)
STEP 10
Multiply row 3 by 11/3:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
0 | 0 | 23 | 50)
STEP 11
Divide row 3 by 23:
(-3 | -2 | 1 | -4
0 | 11 | 5 | 19
0 | 0 | 1 | 50/23)
STEP 12
Subtract 5 × (row 3) from row 2:
(-3 | -2 | 1 | -4
0 | 11 | 0 | 187/23
0 | 0 | 1 | 50/23)
STEP 13
Divide row 2 by 11:
(-3 | -2 | 1 | -4
0 | 1 | 0 | 17/23
0 | 0 | 1 | 50/23)
STEP 14
Add 2 × (row 2) to row 1:
(-3 | 0 | 1 | -58/23
0 | 1 | 0 | 17/23
0 | 0 | 1 | 50/23)
STEP 15
Subtract row 3 from row 1:
(-3 | 0 | 0 | -108/23
0 | 1 | 0 | 17/23
0 | 0 | 1 | 50/23)
STEP 16
Divide row 1 by -3:
(1 | 0 | 0 | 36/23
0 | 1 | 0 | 17/23
0 | 0 | 1 | 50/23)
STEP 17
Collect results:
Answer: | 
 | {x = 36/23
y = 17/23
z = 50/23