3x3 system: x + y - z = -1, x + y + z = 3, 3x - 2y - z = -4

[ulrichsk8ter]

alright my honors algebra 2 teacher didnt feel like teaching today so she said learn it yourself. so heres my problem. i got 3 of them done but this one is tricky:

x+y-z=-1
x+y+z=3
3x-2y-z=-4

someone told me first solve for x using substitution they y and eventually z but i couldnt come up with the answer the book lists as (0,1,2) im really terrible in algebra abut i have a 97 in trig so.....yah plz helps and dont say show any work casue my work is scribble scrabble and i just dont know what to do.

 

[Loren]

Why don't you subtract the 2nd equation from the first (or vica versa) and solve for z right off the bat? Then substitute from there.

 

[ulrichsk8ter]

i figured it out. it was something like substituting the first equation into the 2nd and getting 0 for x then plug it into the equation you got somewhere in the work to get 1 for y then plug both into the top equation and solve getting z as 2