PLEASE HELP
1.) x+y+z=-1
2x-y+2z=-5
-x+2y-z=4

Question

PLEASE HELP
1.) x+y+z=-1
    2x-y+2z=-5
    -x+2y-z=4

anonymous · Answer

I have -x-y-z=-1
            2x+3y=3             those are my two separate answers now what?

hero · Answer

Just hang on a minute. I will solve this first, then explain.

anonymous · Answer

thank you!

hero · Answer

Okay, so here's what we can do here:

hero · Answer

1) Combine the 1st and 3rd equations together

hero · Answer

When you do that you will end up with 

3y = 3

then
y = 1

hero · Answer

Next, go ahead and replace y with 1 in each equation:
x+1+z=-1
2x-1+2z=-5
-x+2(1)-z=4

hero · Answer

Notice that when you do that you'll end up with
x + z = -2
x + z = -2
x + z = -2

anonymous · Answer

no u don't, I combined the 1st and 3rd equation and I got 2x+3y=3     ????

hero · Answer

Try to figure out how I got that.

hero · Answer

Each equation is the same

hero · Answer

I'll show you how to combine the 1st and 3rd equations

hero · Answer

x+y+z=-1
    2x-y+2z=-5
    -x+2y-z=4|dw:1384991486512:dw|