It is possible to use both the Substitution and Elimination Methods to solve a 3 by 3 system using SUBSTITUTION.

Answer 1

yes...

x+ y + z = 3

x = 1

y =1

Substitution:

1 +1 + z = 3

2 + z = 3

z = 1

elimination:

subtracts equation1 MINUS equation 2:

y+z = 2 <-- call this equation ALPHA

subtracts equation 3 from equation ALPHA

z = 1