SOLUTION: hi, i an usually good with systems but this one is giving me trouble and i have a test tomorrow and could really use some help! 3x+2y=12 -4x+5z=12 y-4z=-13 thanx!!!

Question 13893: hi, i an usually good with systems but this one is giving me trouble and i have a test tomorrow and could really use some help!
3x+2y=12
-4x+5z=12
y-4z=-13
thanx!!!
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
1)
2)
3) Solve this for y: and substitute into equation 1)
1) Simplify.

1a) Now take equation 2)
2) Multiply equ. 1a) by 4 and equ. 2) by 3.
1b)
2a) Now add these two to eliminate the x-term.
Divide both sides by 47.
Substitute this into and solve for y.

Substitute this into equation 1) and solve for x.

x = 2
y = 3
z = 4

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