Ordered Triples, why is my answer is wrong???

[vicki]

I am taking a class online at the community college and the software says my answer is wrong, it's working for me..... but I'm probably wrong somewhere, can some one please tell me why I've been kicking myself since playing with this last night
The equations are

x+y+z=8 (1)
2x+5y+2z=25 (2)
-x+9y-3z=12 (3)

My answer I typed in was 10,3,-5

I would really appreciate some help on this one, please.

Forgot to add I added (1) and (3) then did (1) and (2) to eliminate x.

 

[daon2]

I am taking a class online at the community college and the software says my answer is wrong, it's working for me..... but I'm probably wrong somewhere, can some one please tell me why I've been kicking myself since playing with this last night
The equations are

x+y+z=8 (1)
2x+5y+2z=25 (2)
-x+9y-3z=12 (3)

My answer I typed in was 10,3,-5

I would really appreciate some help on this one, please.

Forgot to add I added (1) and (3) then did (1) and (2) to eliminate x.

Your solutions do not satisfy equations (2) or (3).

But how are we supposed to know why your answer is wrong?

 

[vicki]

Your solutions do not satisfy equations (2) or (3).

But how are we supposed to know why your answer is wrong?

Just retried checking 2 and got a different answer than I did the first "5"!!! times, still confused and working

 

[vicki]

Redone still lost let me show more work

x+y+z = 8
-x-9y=3z=12

add
10y-2z=20

Now 1 and 3
2x+5y+2z=25
-2x+-2y-2z=-16
3y 9


y=3
30-2z - I figure now 5 or -5 * 2 =10 will solve , I think this is where I'm going wrong

 

[vicki]

GOT IT , almost had it and didnt realize it. That neg- . Basic Arithmetic took me hours, lol
0,5,3. Last time I posted I was close, I had to post it do my math in black sharpie to get it, lol.
Sorry to waste any time.