Question 992502
.
<pre>
- x - y -2z =   9,     (1)
-2x -2y - z =   1,     (2)
- x - y + z = -10.     (3)


Distract equation &nbsp;(1) &nbsp;from &nbsp;equatin (3). &nbsp;You will get

3z = -10 -9 = -19.     (4)


Now multiply equation &nbsp;(3) &nbsp;by &nbsp;2 &nbsp;and then distract the equation &nbsp;(2). &nbsp;You will get

3z = 2*(-10) - 1 = -20 -1 = -21.     (5)


You have two equations for &nbsp;z, &nbsp;(4) &nbsp;and &nbsp;(5), &nbsp;and they are inconsistent.


Hence, &nbsp;the original system is inconsistent.


<U>Answer</U>. &nbsp;This system has no solutions.



By the way, &nbsp;the determinant of the system is equal to zero.
</pre>