Question

If you were to use the substitution method to solve the following system, choose the new system of equations that would result if x was isolated in the first equation.

x – 6y + 3z = 0
2x – 5y + 8z = 7
x + 7y – 4z = 13

–17y + 14z = 7
y – z = 13

7y + 2z = 7
13y – 7z = 13

13y + 7z = –13
–19y + 16z = –19

y – z = –13
9y + 0z = –19

Answer 1

x - 6y + 3z = 0
x = 6y - 3z

2x - 5y + 8z = 7
2(6y - 3z) - 5y + 8z = 7
12y - 6z - 5y + 8z = 7
7y + 2z = 7

x + 7y - 4z = 13
6y - 3z + 7y - 4z = 13
13y - 7z = 13

third one is your answer

Answer 2

how did you figure it out because I tried solving and I got
7y+2z=7
-19+16z=-19
but that isn't an answer choice

Answer 3

well ...you got the first one
For the second one....I just subbed 6y - 3z in for x in the third equation.

Answer 4

where did u get it from?

Answer 5

get what from ?

Answer 6

I don't understand what you are asking

Answer 7

did you get 6y - 3z for x ?

Answer 8

no?

Answer 9

you have to isolate x from the first equation
x - 6y + 3z = 0
first add 6y to both sides
x - 6y + 6y + 3z = 0 + 6y
combine like terms
x + 3z = 6y
then you will subtract 3z from both sides to get x by itself
x + 3z - 3z = 6y - 3z
combine like terms
x = 6y - 3z
do you understand ?

Answer 10

ok yeah

Answer 11

once you get x by itself, then you sub in what you got for x in the second equation, then in the third equation...does that make sense to you ?

Answer 12

yes thanks

Answer 13

your very welcome .....any more questions ?

Answer 14

are you from texas?

Answer 15

yes

Answer 16

ok im done :) thanks

Answer 17

lol....no problem :)