Question

Elimination help

Answer 1

try to eliminate z .... so you have to...

Answer 2

how do i eliminate z?

Answer 3

subtract the third equation from the second

Answer 4

u most make into a negative tho

Answer 5

can you guys right it out im so confused right now

Answer 6

then subtract this new equation from the top equation and get rid of x then solve for the rest

Answer 7

im trying to xD

Answer 8

or maybe bill could explain better

Answer 9

Thank you, I suck at math .

Answer 10

i just need to see the equations

Answer 11

okay:

(3x+4y+2z)-(x+3y+2z)=0-1

Answer 12

What does this give you?

Answer 13

2x+y+z?

Answer 14

the zs are eliminated (2z-2z=0)

Answer 15

Whats next?

Answer 16

subtract 2x from both sides to get y=-(2x+1)

Answer 17

and then we would add?

Answer 18

no now you substitute this value for y into all of the equations:

2x-2(2x+1)+z=-5 etc.

Answer 19

where theres a y?

Answer 20

yeah

Answer 21

what are these equations?

Answer 22

2x-2(2x+1)+z=-5

Answer 23

https://www.khanacademy.org/math/algebra-basics/core-algebra-systems/core-algebra-systems-tutorial/v/solving-systems-of-equations-by-elimination

The link above is to a video where there are two variables but he elimination step is the same I suggest you watch the other videos as well and go to youtube and search elimination
I know how You feel I was once there with no hope. same type of question too

Answer 24

2x-2(2x+1)+z=-5
3x-4(2x+1)+z=0
x-3(2x+1)+z=1

Answer 25

just realized you only really needed the top equation.

Here we have from the top equation:

2x-2(2x+1)+z=-5
-2x-2+z=-5

-2x+z=-3

z=-3+2x

Answer 26

so we didnt need to add it to the three

Answer 27

substitute this z value in for one of the equations and simplify

Answer 28

only need to do that if you're using elimination

Answer 29

which one?
the second one?

Answer 30

yeah I used the second equation

Answer 31

once you get the x value you just plug that x-value into the equations we figured out for the other variables: y=-2x-1, z=-3+2x

Answer 32

what do you get?

Answer 33

y=x z=5x

Answer 34

Can you show me your work when you substituted for the second equation?

Did it start with:

3x+4(-2x-1)+2(-3+2x)

Answer 35

oooooooh

Answer 36

hold on

Answer 37

i dont understand what to do here
i add them?

Answer 38

just simplify the equation and combine like terms

Answer 39

how would i simplify?

Answer 40

2x + 3x = 5x
(3 + 5x + 2x2)

Answer 41

?

Answer 42

3x+4(-2x-1)+2(-3+2x)
3x-8x-4-6+4x

-x-10=0

x=-10
y=19
z=-23

Answer 43

now do you understand?

Answer 44

i believe so. i still need more practice with all of this but you've helped me so much.