(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Solve the following (obviously using matrices):

a=[2 1 1 3 8; 3 -1 4 7 7; 0 1 -1 -1 2; 1 -1 2 3 1]

2. Relevant equations

3. The attempt at a solution

OK so my linear algebra prof is useless. So I am now on my own (well plus the infinite power of the internet that is!)

So on our assignment, we must solve the following system

a=[2 1 1 3 8; 3 -1 4 7 7; 0 1 -1 -1 2; 1 -1 2 3 1] (where each ; denotes a new line in the matrix, so in total there are 4 rows and 5 columns. Note: This is an augmented matrix.)

So, no matter WHAT I do in row reducing, I always seem to get two rows of complete zeroes on the bottom, which leaves me with only 2 leading variables, and 2 free variables. The only problem is, since I have 4 unknowns and 4 equations, shouldn't it be very possible for me to find what each variable is equal to?

Thanks!

PS: the system I CONTINUOUSLY get is the following:

a=[1 0 1 2 3; 0 1 -1 -1 2; 0 0 0 0 0; 0 0 0 0 0]

Thanks so much in advance!

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# Question about how to solve a simple matrix (beginner linear algebra).

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