Question

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

not understanding this

Answer 1

are you familiar with the elimination method ?

Answer 2

Cramer's rule?

Answer 3

errrrm no

Answer 4

i dont know what elimantion methid is

Answer 5

Has they mentioned in which method you have to do this? @openstudy2222222

Answer 6

think its elimantion methid but idk how to do that @Ⓐ uri

Answer 7

take the first two equations and add them...can you do that ?

Answer 8

the z's will cancel out

Answer 9

yes ^_^ @kelliegirl33

Answer 10

add them and let me see what you get

Answer 11

i got 36 :\

Answer 12

no.....let me show you....hold on

Answer 13

3x - y - z = 3
-2x + 3y + z = -3
----------------add
x + 2y = 0

do you see how I did that ?

Answer 14

OH
i see :)

Answer 15

now we have to take the last two equations and cancel out the z's. Sometimes when doing this we have to multiply an equation by a number to make the z's opposite...one positive and one negative with the same coefficient. I understand how this can be confusing so I will show you...hold on

Answer 16

-2x + 3y + z = -3 -->(2)-2x + 3y + z = -3
4x - 2y - 2z = 2
----------------
-4x + 6y + 2z = -6 (result of multiplying by 2)
4x - 2y -2z = 2
----------------
wait.....there is a problem....the x's are cancelling out also...let me try something....give me a second

Answer 17

Let me try to eliminate the y's
3x - y - z = 3 -->(3)3x - y - z = 3
-2x + 3y + z = -3
----------------
9x - 3y - 3z = 9 (result of multiplying by 3)
-2x + 3y + z = -3
-----------------add
7x - 2z = 6

now take the last 2 equations and eliminate the y's
-2x + 3y + z = -3 -->(2)-2x + 3y + z = -3
4x - 2y - 2z = 2 -->(3)4x - 2y - 2z = 2
--------------------
-4x + 6y + 2z = -6 (result of multiplying by 2)
12x - 6y -6z = 6 (result of multiplying by 3)
--------------------add
8x - 4z = 0

I have eliminated the y's. I want you to look over this and ask any question about anything you do not understand. Take your time...I will wait

Answer 18

okay so to elimate the y's do you have to multiply the top i still lost can yu explain it a lil more :[

Answer 19

The elimination method...you have to eliminate a variable....either x,y,or z. I have just eliminated the y's. To do this there are times when you have to multiply to get the variables to cancel out. For instance, -4x and 4x will cancel out the x's. But if you have -2x and 3x, you would have to multiply one equation by 3 and one equation by 2 and then you would get -6x and 6x and they would cancel. Sometimes you have to multiply both equations, sometimes just 1 and sometimes none. Is this making any sense to you ?

Answer 20

why did you log off......when you decide to get back on, tag me, and we will finish this problem.