How do you solve x plus y plus z equals 7 2x plus 3y-z equals -2 5x-6x plus 3z equals 36?

Answer 1

Let me see:

1) x + y + z = 7 y = 7 - x- z
2) 2x + 3y- z = -2
3) -x + 3z = 36 x = 3z - 36


Subst. 3) into 2):

2(3z-36)+3y -z = -2

Subst 1) into 3):

2(3z-36) +3(7-x-z) - z = -2

Subst 3) into 2) again:

6z-64 + 3(7-(3z-36) - z) -z = -2
z= 67/7

Subst answer into 3) -x + 3(67/7) = 36
x = -51/7

Subst answers into 1):
-51/7 + y + 67/7 = 7
y = 33/7

therefore x = -51/7, y = 33/7, z = 67/7