SOLUTION: I am having some difficulty with an equation. I worked it out, atleast I thought I did, and I got a totaly different answer then the real answer. 4x-3y+7z=38 x+4y+z=16 5y-z

Question 44373: I am having some difficulty with an equation. I worked it out, atleast I thought I did, and I got a totaly different answer then the real answer.
4x-3y+7z=38
x+4y+z=16
5y-z=6
my final was x=45, y=-2, z=-21
According to my assignments, it was totaly different.
Can you help me with this equation please.
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
Solve the system of equations:
1)
2)
3)
Rewrite equation 3) as:
3a) and substitute into equations 1) and 2) to eliminate the variable z.
1a)
2a)
Simplify 1a) and 2a)
1b)
2b)
Multiply equation 2b) by 4 and subtract equation 1b) from it.
2b)
1b) -
4) Divide bothe sides by 4.
Substitute this into equation 3a) and solve for z.

Finally, substitute y=2 and z=4 into equation 2 (or into equation 1) and solve for x.
2)

Check: Substitute x = 4, y = 2, and z = 4 into the three original equations.
1) = 38 It checks!
2) = 16 It checks!
3) = 6 It checks!

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