explain, in complete sentences, which method would you use to solve the following system of equations. Also explain why this method was chosen. provide solution.
x-3y+4z=-9
2x+y+3z=6
x-4y+3z=-9

Question

jhonyy9 · Answer

subtract 3rd from first equation 

x-3y+4z=-9
x-4y+3z=-9
------------
0    y+z=0

jhonyy9 · Answer

like first step

jhonyy9 · Answer

like second step multiply first by -2 and assum with second 

-2x+6y-8z=18
  2x+y+3z=6
---------------
  0   7y-5z=24

jhonyy9 · Answer

so than we know tha y+z=0 so y=-z so this substitute in 7y-5z=24 and will get
7(-z)-5z=24 so -7z-5z=24 so -12z=24 so z=24/(-12) = -2
so z=-2 
so y=-(-2)=2

2x+y+3z=6
2x+2+3(-2)=6
2x+2-6=6
2x-4=6
2x=10
x=10/2 
x=5

x=5
y=2
z=-2