solve the system of linear equations using the Gauss- Jordan elimination method

Question

x1- x2+ 4x3 = 15
x1+ x2 = X3 = 4
-3X1-X2 + X3 = -2

Answer 1

There is probably a typo in the second equation. The first equal sign (between x2 and x3) should be a + or a -.
x1+ x2 = X3 = 4

Curiously both corrections using a + or - give integer solutions.

Next, Gauss-Jordan elimination requires the matrix be transformed into a diagonal matrix using elementary row operations. After that, the solution should be evident.

If you are not yet familiar with the method, try reading your textbook, or visit:
http://ceee.rice.edu/Books/CS/chapter2/linear44.html

If you have questions about the method, give it a try and post up to the point where you have a problem or question.