1) Solve the system using elementary row operations on the equations of the augmented matrix. Follow the systematic elimination proceedure.
xsub1 +5xsub2 = 7
-2xsub1 - 7xsub2 = -5
2) Find the point of intesection of the lines xsub1 - 5xsub2 =1 and 3xsub1 - 7xsub2 = 5
3) What is a row operation in matrices? What you do to transform it from the augmented matrix to the triangular form where you have a row of ones and 0's under and above the leading ones?
4) Solve the system.
xsub2 + 4xsub3 = -5
xsub1 + 3xsub2 +5xsub3 = -2
3xsub1 + 7xsub2 + 7xsub3 = 6