Question 185247
Solve the system of equations
8x - y + z = 34
3x +2y -3z =-15
 x -3y +2z = 29
Type an exact answer in simpliest form
:
8x - y + z = 34
3x +2y -3z =-15
 x -3y +2z = 29
-------------------adding the 3 equation will eliminate z
12x - 2y = 48
Simplify, divide 2:
6x - y = 24
:
multiply the 1st by 3, add to the 2nd equation
24x - 3y + 3z = 102
 3x + 2y - 3z = -15
-------------------------adding eliminate z again
27x - y = 87
:
Subtract (6x - y = 24) from the above equation
27x - y = 87
 6x - y = 24
-------------
21x = 63
x = {{{63/21}}}
x = 3
:
Find y using 6x - y = 24
6(3) - y = 24
18 - y = 24
-y = 24 - 18
-y = +6
y = -6
:
Find z using the 3rd equation
x -3y + 2z = 29
3 - 3(-6) + 2z = 29
3 + 18 + 2z = 29
2z = 29  - 21
2z = 8
z = {{{8/2}}}
z = +4
;
;
Check solution in the 2nd equation:
3x +2y -3z =-15
3(3) = 2(-6) - 3(4) = -15
9 - 12 - 12 = -15; confirms our solutions