Question

can someone help me solve this using elimination?
5x-y+z=4
x+2y-z=5
2x+3y-3z=5

Answer 1

@Destiny_forever

Answer 2

@mathmate

Answer 3

I've watched all the stuff my teacher has asked us to and I still dont understand

Answer 4

hint: "add" the first two equations together. that will eliminate the "z" variable

Answer 5

I did that my final thng that i got was 4x-y= 9 but after that ig et stuck

Answer 6

I can help! :)

Answer 7

Okay.

Lets first use the first equation. Lets add the y and subtract 5x from both sides.

When we do this we get:
\[z = 4 + y - 5x\]

Answer 8

wait wouldnt it become 4 x?

Answer 9

Yes! Good! I was just going step by step. But good job!

Answer 10

Also did you bring the z to the oppiste side of the equal side? if so why???

Answer 11

Well, It depends on how you solve it. But you always want the variable you want to solve for first on a seperate side than anything else.

Answer 12

So when you solve the three equations in such a way you should get:

\[x = 1\]
\[y = 3\]
\[z = 2\]

Answer 13

Hope this helped! Have a great day!

Also a medal would be much appreciated! Just click best response next to my answer. Thank You!

Also, a fan will be much appreciated as well! Just hover over my avatar and click “Become a fan”. This will tell you whenever I am online so you can ask me for help in any of your other questions!

If you see that I am online and need help with a question, just tag me in your question!

@Candycane

Answer 14

okay. But how do I solve to get those numbers??

Answer 15

This is for extra credit to bring up my grade and it is required to show all the steps, I'd ask my teacher but i wont hear from her for two weeks due to winter break

Answer 16

Well.. try this it should help:

http://www.montereyinstitute.org/courses/DevelopmentalMath/COURSE_TEXT2_RESOURCE/U14_L2_T2_text_final.html

Answer 17

Nope.. Im still slightly stuck...

Answer 18

@Zarkon

Answer 19

@Agl202

Answer 20

I only have a few minutes so I'll do my best to help you...

You have two equations..
\[5x-y+z=4\] \[x+2y-z=5\]
So just find something that is easy to eliminate first... like z because they are the same value, just opposite signs (which is what you want so they can be crossed out).

Now you're left with 5x - y = 4
and x + 2x = 5

Answer 21

Now you're going to do the exact same thing with the 2nd and last equations (because the first time we did it, it was the first and second equations..)

So x + 2y - z = 5
and 2x + 3y - 3z = 5

you HAVE to eliminate z again since you did it the first time..

so in order to make it where you can eliminate it, you need to multiply the whole equation by -3..
so -3x - 6y + 3z = -15
and 2x + 3y - 3z = 5
which gives you
-x - 3y = -10


and the very first equation you did was 4x + y = -1

Answer 22

Let me correct myself.. the very first one would end up to be 6x + y = 9 lol

Answer 23

continue the process I have to go.