|
Question 186521: Please help me with this problem tonight please.
8x-y+z=-4
3x+2y-3z=9
x-3y+2z=-11
Pu in simpliest form
Answer by dukesmart(20)   (Show Source):
You can put this solution on YOUR website! Please help me with this problem tonight please.
8x-y+z=-4 (1)
3x+2y-3z=9 (2)
x-3y+2z=-11 (3)
here is my solution:
x-3y+2z=-11 ====> -3x+9y-6z=33 (4)
take (2) + (4) ====> 11y-9z=42 (5)
x-3y+2z can be written: -8x+24y-16z=88 (6)
take (1) + (6) ===> -y+24y+z-16z=-4+88 ==> 23y-15z=84 (7)
(5)====>11y-9z =42
(7)====>23y-15z=84 ==>-23y *3/5 + 15z *3/5 = -84*3/5
==>-69y/5 +9z = -252/5 (8)
take (5) + (8) ===> 11y - 69y/5 -9z +9z = 42-252/5
===>11y-69y/5=42-252/5
===>55y-69y=210-252
===>-14y = -42
===> y=42/14 ====> y=3
(5) 11y-9z=42 then if y=3 then 11*3-9z=42 ====>9z=-42+33=9 ===z=-1
Now We have y=3, z=-1 then replace them in equation (1):
8x-y+z=-4===> 8x-3-1=-4 ===> x=0/8=0
reply: x=0,y=3, z=-1
|
|
|
| |
