Question

reviewing for exam...can someone help me work through this?
Solve....
x-y+z=0
3x-2y+6z=9
-x+y-2z=-2

Answer 1

x - y + z = 0 -->(-3)
3x - 2y + 6z = 9
-----------------
-3x + 3y - 3z = 0 (result of multiplying by -3)
3x - 2y + 6z = 9
-----------------add
y + 3z = 9

3x - 2y + 6z = 9
-x + y - 2z = -2 -->(3)
---------------
3x - 2y + 6z = 9
-3x + 3y - 6z = -6 (result of multiplying by 3)
--------------add
y = 3

y + 3z = 9
3 + 3z = 9
3z = 9 - 3
3z = 6
z = 2

x - y + z = 0
x - 3 + 2 = 0
x - 1 = 0
x = 1

check...
3x - 2y + 6z = 9
3(1) - 2(3) + 6(2) = 9
3 - 6 + 12 = 9
-3 + 12 = 9
9 = 9 (correct)

x = 1, y = 3 and z = 2

Answer 2

thanks so much!

Answer 3

anytime :)