X+ y + z = 12
6x - 2y - z = 16
3x + 4y + 2z = 28

x = 4

y = 0

z = 8

Step-by-step explanation:

Step 1: Multiply first equation by −6 and add the result to the second equation. The result is:

 x3 x+y −8y + 4y + z −7z + 2z = 12 = −56 = 28

Step 2: Multiply first equation by −3 and add the result to the third equation. The result is:

 x+    y−   8 y+    y+    z−   7 z−     z = 12 = −56 = −8

Step 3: Swap Row 2 and Row 3.After this step we have:

 x+    y+    y−   8 y+    z−     z−   7 z = 12 = −8 = −56

Step 4: Multiply second equation by 8 and add the result to the third equation. The result is:

 x+    y+    y+    z−     z−   15 z = 12 = −8 = −120

Step 5: solve for z.

−15 zz=−120=8

Step 6: solve for y.

y−zy−8=−8y=−8=0

Step 7: solve for x by substituting y=0 and z=8 into the first equation

step-by-step explanation: