solve the following system of equations???

[Elizabeth123]

Solve the following system of equations

x + y - z = -1
4x - 3y + 2z = 16
2x - 2y - 3z = 5

We are supposed to find X, Y and Z. In class the teacher did a similar problem to this using the elimination method (multiplying the top by -4 to eliminate x from the 1st and 2nd equations) and a bunch of other eliminations. I cannot figure this equation out.

 

[Deleted member 4993]

Solve the following system of equations

x + y - z = -1....................................................(1)
4x - 3y + 2z = 16...............................................(2)
2x - 2y - 3z = 5.................................................(3)

We are supposed to find X, Y and Z. In class the teacher did a similar problem to this using the elimination method (multiplying the top by -4 to eliminate x from the 1st and 2nd equations) and a bunch of other eliminations. I cannot figure this equation out.

Please share with us your work, indicating exactly where you are stuck - so that we know where to begin to help you.

multiplying the top by -4 to eliminate x from the 1st and 2nd equations <<< This is correct

after that we get

x + y - z = -1....................................................(1)
0 -7y + 6z = 20 ....................................................(4)
2x - 2y - 3z = 5.................................................(3)

Now continue by multiplying the top by -2 to eliminate x from the 1st and 3rd equations

x + y - z = -1....................................................(1)
0 -7y + 6z = 20 ....................................................(4)
0 - 4y - z = 7.................................................(5)

Now equations (4) and (5) have only 'y' and 'z' - two equations and two unknowns.

Solve for those and go back to (1) to solve for 'x'.