SOLUTION: Solve the system of equations. If the system has no solution, say it is inconsistent. x + y + z = 3 x - z = 1 y - z = -4

Algebra ->  Inequalities -> SOLUTION: Solve the system of equations. If the system has no solution, say it is inconsistent. x + y + z = 3 x - z = 1 y - z = -4      Log On


   



Question 918085: Solve the system of equations. If the system has no solution, say it is inconsistent.
x + y + z = 3
x - z = 1
y - z = -4

Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
Adding (1) and (2) leads to
(x+y+z)+(x-z)=3+1
2x+y=4
(4) y=4-2x
Adding (1) and (3) leads to
(x+y+z)+(y-z)=3-4
x+2y=-1
Replacing y with (4) leads to the solution for x:
x+2(4-2x)=-1
x+8-4x=-1
-3x=-9
x=3
Using x we can find y:
y=4-2x=4-2(3)=4-6=-2
y=-2
Next we find z:
x+y+z=3
3-2+z=3
-2+z=0
z=2


solution: (3, -2, 2)