PLZ!!!!! I need help! solve by elimination: x - y - 2z = 4 , -x + 2y + z = 1, and -x + y - 3z = 11.

Question

 Write your answer as a point, an ordered triple: (x,y,z), without spaces.

x - y - 2z = 4

-x + 2y + z = 1

-x + y - 3z = 11.     

Answer 1

add equation 1 to 2

y-z=5

subtract equation 2 from 3

y+4z=-10

 

solving these 2 equations by subtracting them

 

-5z=15 ----->z=-3

 

substitute in one of the above equations

y-(-3)=5 ----->y=5-3=2

 

Substitute in one of the first equation

x-2-2(-3)=4 ----->x+4=4 ----->x=0

 

The solution is x=0, y=2, z=-3