Review 2

Solving a System Using Gaussian Elimination 

Write the system of equations in an augmented matrix.  Use elementary row operations to get the matrix into row-echelon form or reduced-row echelon form to solve the system.



#1)  5x + 4y = −30
       3x − 9y = −18

#2)  −2x − 9y = −25
       −4x − 9y = −23

 #3)  −6x − 2y − z = −17
          5x + y − 6z = 19
         −4x − 6y − 6z = −20

#4)  −5x + 3y + 6z = 4
       −3x + y + 5z = −5
       −4x + 2y + z = 13

In addition to Gaussian Elimination, review all types of matrices exercises that we have covered this year.

#1)  (−6, 0)
#2)  (−1, 3)
#3)  (2, 3, −1)
#4)  (−2, 4, −3)