Question

Solving Systems of Linear Equations in Three Variables
-2x-3y-6z=-26
5x+5y+4z=24
3x+4y-5z=-40

Answer 1

hi are you familiar with matrices ?

Answer 2

or determinants?you can solve them using matricews or determinants

Answer 3

what subject are you in? algebra?

Answer 4

yes algebra 2 but i have to use the linear combination method

Answer 5

ok, so you can solve it by elimination method

Answer 6

not really

Answer 7

-2x-3y-6z=-26 eq (1)
5x+5y+4z=24 eq(2)
3x+4y-5z=-40 eq (3)

Answer 8

multiply eq 1 by 3, multiply eq 3 by 2

Answer 9

ok ill do that right now

Answer 10

on eq 1 you get -6x-9y-18z=-78
on eq 3 you get 6x+8y-10z=-80

Answer 11

then you can add them together,to get -y-28z=-158 ......eq (4)

Answer 12

now on the same prob multiply eq 1by 5 and
eq 2 by 2

Answer 13

ok

Answer 14

on eq 1 you get -10x-15y-30z=-130
on eq 2 10x+10y+8z=48 add them together to get
-------------------------
0-5y-22z=-82

Answer 15

0-5y-22z=-82 eq 5 now mult eq 4 by -5 to get
5y+140z=790 eq 6 add them together to get
----------------
118z=708
z=708/118
z=6

Answer 16

okay hold up a sec.

Answer 17

im getting a bit lost

Answer 18

on where?

Answer 19

take your time..... your getting in there now

Answer 20

equation 4 (-5) -1y-28z=-158
equation 5 -5y-22z=-82

5y+140z=-290
-5y-22z=-82

right?

Answer 21

what do i multipy equation 6 by?

Answer 22

how did you get this 5y+140z=790

Answer 23

now once you get z=6 , subs this to eq 4 to get y =-10

Answer 24

how did you get 790 on equation 4?

Answer 25

from eq 4 mult it by 5 to get
5y+140z=790

Answer 26

oh right right i accidentally wrote -58 instead of -158

Answer 27

ok, then follow the next step

Answer 28

so equation 4 with -1y-28(6)=-158?

Answer 29

yes correct

Answer 30

yes california so i did it with the other equation -5y -22(6)=-82 and got y=-10

Answer 31

yes correct

Answer 32

then subs them to another equations to get x

Answer 33

i sub them to the equations from the beginning right?

Answer 34

yes subs them to get the x

Answer 35

so i sub everything to the equation 2 and im getting a fraction
5x+5(-10)+4(6)=24
5x-50+24=24
5x-26=24
5x=50
x=10
:D i got it.... Thank you sooooooooooooo much!!!

Answer 36

its really nice of you taking your time to help me :)

Answer 37

yw.....ok gud luck now