SOLUTION: Need to solve this system.i keep getting stuck. 3x+4y+z=7 2y+z=3 -5+3y+8z=-31

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Question 584842: Need to solve this system.i keep getting stuck.
3x+4y+z=7
2y+z=3
-5+3y+8z=-31
Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
start with 2y%2Bz=3 solve for z
z=3-2y
next look at -5%2B3y%2B8z=-31 solve for y
3y%2B8z=-26 substitute what z =
3y%2B3-2y=-26
y%2B3=-26
y=-23
find z
z=3-2y
z=3-2%28-23%29
z=3-%28-46%29
z=49
find x with last equation
3x%2B4y%2Bz=7
substitute for y and z
3x%2B4%28-23%29%2B%2849%29=7
3x%2B%28-92%29%2B%2849%29=7
3x%2B%28-43%29=7
3x=50
x=50%2F3