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June 28th, 2017, 01:15 PM  #1 
Newbie Joined: Jun 2017 From: Wisconsin Posts: 15 Thanks: 0  Solving a System of Equations with GaussJordan Method
I'm a little stuck on a problem using the GaussJordan method of matrices. The problem asks to solve the following set of equations: x + 2y + 3z = 2 2x + 2y  3z =27 3x + 2y + 5z = 10 I put into an augmented matrix: 1 2 3 = 2 2 2 3 = 27 3 2 5 = 10 So my goal was to get all the 0's first then make the coefficients 1. Step 1: (Make 2 and 3 0 in R2 ad R3 in the first column) 2R1 + R2 > R2 3R1 + R3 > R3 1 2 3 = 2 0 2 9 = 23 0 4 4 = 4 This is where I'm stuck. I want to make 2 and 4 0 in column 2 R1 and R3. Can I do R1 +R2 > R1 since 2 and 2 cancel each other out? This is not a hard matrix but I'm a little tripped. I did get a little further but I got confused. Here is the rest of my math: Step 2: Make 2 and 4 0 in col 2 R1 and R3 R1 + R2 > R1 2R2 + R3 > R3 1 0 6 = 25 0 2 9 = 23 0 0 14 = 42 Step 3: Make 6 and 14 0 in col 3 R1 and R2 9R1 + 6R > R1 14R2 + 9R3 > R2 I also got confused here because my zero was replaced with a number like this: 9 12 0 = 87 Any help would be greatly appreciated. Thank you. 
June 28th, 2017, 04:31 PM  #2 
Newbie Joined: Jun 2017 From: Long Beach Posts: 20 Thanks: 0 
your third matrix, starting from the augmented matrix, should read: 1 0 6  25 0 2 9  23 0 0 14  42 Last edited by mgho; June 28th, 2017 at 04:35 PM. 
June 28th, 2017, 06:24 PM  #3 
Newbie Joined: Jun 2017 From: Wisconsin Posts: 15 Thanks: 0 
Ok thank you!


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equations, gaussjordan, method, solving, system 
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