Question

Solve: 2x + 3y + z = -3
x + 4y - 3z = -23
3x - y +2z = 14
I don't even know how to start this problem:(

Answer 1

have u learnt Cramer's rule?

Answer 2

or the matrix method?

Answer 3

No I have not. At least I don't believe so. I know I need to reduce the problem down to like 2 equations

Answer 4

then which method would u adopt for the solution?

Answer 5

we can reduce the equations into two variables n two equtations

Answer 6

would I need to set the equations equal to zero and factor?

Answer 7

no u have to eliminate one variable, then solving them simultaneously

Answer 8

like, we can choose eq 1 and 2 n eliminate x,say

Answer 9

likewise we can select eq 2 n three, again eliminate x

Answer 10

we get a et of two eqs in 2 variables

Answer 11

got it?or u need the solution?

Answer 12

Can you show me the steps? That would help me a lot.

Answer 13

I am studying for my final and this is a practice problem I am doing, I just can't figure it out.

Answer 14

multiply eq 2 with 2 and subtract eq 1 and 2
2x+3y+z=-3
2x-2y+4z=28
----------------------
5y-3z=-31(on subtraction)

Answer 15

right?

Answer 16

similarly multiplying eq 2 by 3 and subtracting 2 and 3

Answer 17

3x+12y-9z=-69
3x-y+2z=14
---------------
-13y-11z=-83

Answer 18

is it ok?

Answer 19

yes, Thank you.

Answer 20

now there r two equations in two variables
u can use either substitution method or elimination method

Answer 21

2x+3y+z=-3
2x+8y-6z=-46
---------------
-5y+7z=-43

Answer 22

i missed the multiplication by 2 first :(

Answer 23

I don't know, its just still very confusing to me. So can you go back to the beginning..... I have 2x + 3y + z = -3 but where did the equation blow it come from?