SOLUTION: i am absolutly confused on this question ive tried several different angles: 5x+2y+z=-11 2x-3y-z= 17 7x+y2+z= -4

Algebra.Com
Question 130320: i am absolutly confused on this question ive tried several different angles:
5x+2y+z=-11
2x-3y-z= 17
7x+y2+z= -4

Answer by ilana(307)   (Show Source): You can put this solution on YOUR website!
You have 3 equations, call them A, B, and C. First, combine A and B, eliminating z, to get an equation with x and y. Then combine B and C, again eliminating z, to get another equation with x and y. Then you will have a system with 2 equations and 2 variables, which you should know how to solve already.
Adding A and B gives 7x-y=6 (call this D). Adding B and C gives 9x-y=13 (call this E). Change equation D to y=7x-6. Now plug that y into E to get 9x-(7x-6)=13, so 2x+6=13, so 2x=7, so x=3.5. plug that back into D to get y=7(3.5)-6=24.5-6 =18.5. Using equation B, z=2x-3y-17=2(3.5)-3(18.5)-17= 7-55.5-17= -48.5-17=-65.5
So (x, y, z)=(3.5, 18.5, -65.5).

RELATED QUESTIONS

Please help me solve this. I have tried several times but I am missing something or doing (answered by Gogonati,mananth)
I have tried this several different ways. I don't know how to do it. Please help.... (answered by ankor@dixie-net.com)
Dear Tutor, I am getting so many different answers with this...Please help! Direction (answered by scott8148,Alan3354,stanbon)
Solve x, y and z 3x-2y+z=4 5x-3y+2z=7 7x-5y-z=0 (answered by Fombitz)
Please help! I am so confused! 3. Solve for X, Y, and Z in the following systems of... (answered by rviksub)
I am getting confused on Literal Equations. Solve for z: A=2y/z Thank you. (answered by Alan3354)
use matrices to solve this system: 2x+3y+z=2 5x-2y-z=4... (answered by richwmiller)
I am working on distributive property. This is the only question I can not figure out on... (answered by ewatrrr,josgarithmetic,Fombitz)
Use Cramer's Rule to solve for z: 3x+2y-z=17 2x+3y-z=15... (answered by longjonsilver)