Question
Write as a matrix equation and solve each system.
2x + 5y - 2z = 23
3x - 4y + 2z = 5
5x - 6y - 4z = 3
-----------------------------
6x - 6y - 2z = 28
x - 2y = 4 -2x + 5y = -9
2x + 5y - 2z = 23
3x - 4y + 2z = 5
5x - 6y - 4z = 3
-----------------------------
6x - 6y - 2z = 28
x - 2y = 4 -2x + 5y = -9
Answers
oobleck
#1. See
https://www.wolframalpha.com/input/?i=%7B%7B2,5,-2%7D,%7B3,-4,2%7D,%7B5,-6,-4%7D%7D*%7B%7Bx%7D,%7By%7D,%7Bz%7D%7D+%3D+%7B%7B23%7D,%7B5%7D,%7B3%7D%7D
Set up #2 similarly, separating the 2nd compound equality into two equations.
https://www.wolframalpha.com/input/?i=%7B%7B2,5,-2%7D,%7B3,-4,2%7D,%7B5,-6,-4%7D%7D*%7B%7Bx%7D,%7By%7D,%7Bz%7D%7D+%3D+%7B%7B23%7D,%7B5%7D,%7B3%7D%7D
Set up #2 similarly, separating the 2nd compound equality into two equations.