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September 20th, 2011, 05:56 AM  #1 
Newbie Joined: Sep 2011 Posts: 9 Thanks: 0  Linear equation in three variables
What is the value of “y” in the following system of equations? x + y + z = 75 ; 2x + y – z = 15 a. 0 b. 5 c. 15 d. 60 
September 20th, 2011, 08:10 AM  #2 
Global Moderator Joined: Dec 2006 Posts: 20,931 Thanks: 2205 
Is something mistyped or omitted? The equations imply that y = 30 + x/2 = 45  z/3.

September 20th, 2011, 12:42 PM  #3  
Global Moderator Joined: May 2007 Posts: 6,807 Thanks: 716  Re: Linear equation in three variables Quote:
 
September 20th, 2011, 03:31 PM  #4 
Global Moderator Joined: Dec 2006 Posts: 20,931 Thanks: 2205 
With only the two equations, y can't be calculated, but you can calculate 3x + 2z.

September 20th, 2011, 10:38 PM  #5 
Newbie Joined: Sep 2011 Posts: 9 Thanks: 0  Re: Linear equation in three variables
This is it, word for word. Thanks anyway. 

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equation, linear, variables 
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