If you were to use the elimination method to solve the following system, choose the new system of equations that would result after the variable z is eliminated in the first and third equations, then the second and third equations.

x – y + 2z = –2
2x + 2y + z = 7
3x + 3y – z = 3

last one..thnx

Question

If you were to use the elimination method to solve the following system, choose the new system of equations that would result after the variable z is eliminated in the first and third equations, then the second and third equations.

x – y + 2z = –2
2x + 2y + z = 7
3x + 3y – z = 3

last one..thnx

anonymous · Answer

can someone plzz help me?? 

HERO??

anonymous · Answer

mult [3] by 2 and add to [1]
  x – y + 2z = –2  [1]
6x + 6y –2z = 6   [3]'=[3]*2
===========
7x+5y=4   [1]'

Add the given [3] to [2]
2x + 2y + z = 7  [2]
3x + 3y – z = 3   [3]
==========
5x+5y=10  [2]'

The new system is the 2x2 system
7x+5y=4   [1]'
5x+5y=10  [2]'

I checked this one wolfram and the answers match up

anonymous · Answer

THANK YOU SOO MUCH FOR YOUR HELP ON BOTH OF MY QUESTIONS =)