Patrick B. answered 07/24/21
Math and computer tutor/teacher
x + y + z = 4
y - 3z = 11
2x + y + 5z = -5
eq1 - eq2: x + 4z = -7
eq3 - eq2: 2x + 8z = -16 ---> x + 4z = -8
the system is inconsistent.
there is no solution.
checking by Gaussian elimination...
the matrix is:
1 1 1 4
0 1 -3 11
2 1 5 -5
row3 = -2 * row1 + row3
------------------------
1 1 1 4
0 1 -3 11
0 -1 3 -13
row3 = row 2 + row3
--------------------
1 1 1 4
0 1 -3 11
0 0 0 -2


