Question

x-2y+z=6
x+3y+z=16
3x-y-z=2

already solved: y=2

Answer 1

i solved this but the server went down

the roots are x = 3.5, y=2 and z = 6.5.

Answer 2

this is what i got but somehow that's incorrect

Answer 3

oh ive checked it out - lets try again

Answer 4

no -those figures are correct for the equations you posted

Answer 5

plus them into the equations

Answer 6

alright thank u...must be a typo in the back of the book

Answer 7

@jimmyrep, u answered my other question too but i was wondering if u can explain how u got the answer

Answer 8

x-2y+z=6 --- x-2y+z=6
x+3y+z=16 ---------------- x+3y+z=16
3x-y-z=2 ---- 3x-y-z=2 ---- 3x-y-z=2
----------- --------------
4x-3y=8 4x+2y=18
4x-3y=8 / x(-1) --- -4x+3y=-8
4x+2y=18 ---- 4x+2y=18
------------
0 5y=10 --- y=10/5 =2

if y=2 --- 4x-3(2)=8 --- 4x-6=8 --- 4x=14 --- x=14/4 =7/2
x-2y+z=6 --- z=6-x+2y=6-7/2 +4=10-7/2
2z=20-7 --- 2z=13 --- z=13/2

x=7/2
y=2
z=13/2