SOLUTION: 3x+2y=-2 2x-3z=1 0.4x-0.5z=-2.1

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Question 137891: 3x+2y=-2
2x-3z=1
0.4x-0.5z=-2.1

Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
3x + 2y =-2
2x - 3z = 1
0.4x-0.5z=-2.1
:
Multiply the 3rd equation by 10 and arrange to:
2x + 2y + 0z = -2
2x + 0y - 3z = 1
4x + 0y - 5z = -21
:
Multiply the 2nd equation by -2, add to the 3rd equation
-4x + 0y + 6z = -2
+4x + 0y - 5z = -21
----------------------addition eliminates x
0x + 0y + z = -23
z = -23
:
Find x using the 2nd equation
2x - 3(-23) = 1
2x + 69 = 1
2x = 1 - 69
2x = -68
x =
x = -34
:
Find y using the 1st equation:
3(-34) +2y = -2
-102 + 2y = -2
2y = 102 - 2
2y =
y = +50
:
:
Check solution using original 3rd equation:
0.4x - 0.5z = -2.1
.4(-34) -.5(-23) =
-13.6 + 11.5 = -2.1; confirms our solution