Question

3x - 5y + z = 12
x + 6y - z = -4
2x - 5y - 2z = -8

Answer 1

@phi

Answer 2

i have a few others also

Answer 3

use elimination

Answer 4

can you get me started

Answer 5

are you finding the value of x,y and z??
just use elimination method

Answer 6

it might be easiest to change the order of the equations to
x + 6y - z = -4
3x - 5y + z = 12
2x - 5y - 2z = -8

Answer 7

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 second equation.

Answer 8

the equation 1 and 2.first cancel out the z ..

Answer 9

you have to use sub

Answer 10

if we ignore the variables (but keep the same order)

1 6 -1 -4
3 -5 1 12
2 -5 -2 -8

Answer 11

ok

Answer 12

then what

Answer 13

the first step is to make the first column below the 1 all zeros

multiply the first row by -3 and add that to the 2nd row

Answer 14

in other words, multiply -3 * 1 6 -1 -4 to get -3 -18 +3 +12
add those numbers to the 2nd row to get a new 2nd row

Answer 15

these are the options

a. 4x + y = 8
-17y = 0
b. 2x - 11y = 16
4x + 7y = -16
c. -23y + 4z = 24
-17y = 0
d. 13y - 2z = 24
7y - 4z = 0

Answer 16

unless you are Rainmain, you have to go through the steps one by one

Answer 17

haha ok

Answer 18

o-13+4+24

Answer 19

or is it 6-13+4+24

Answer 20

phi you there

Answer 21

First, I am not sure where you got your numbers.

Answer 22

i added both sides together

Answer 23

2nd, looking at the "answers", I don't know what the question is ?

Answer 24

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 second equation.

3x - 5y + z = 12
x + 6y - z = -4
2x - 5y - 2z = -8

Answer 25

In that case, we are not solving for x,y,z . And they tell us to use substitution (which is a lousy way to solve for more than 2 variables... it is too confusing).

But we have to use substitution.

Answer 26

if x was isolated in the second equation.

that means "solve for x" in the equation
x + 6y - z = -4

can you do that ?

Answer 27

yes one second

Answer 28

x=-4+z-6y

Answer 29

next, replace x with -4 + z -6y in the first equation and the 3rd equation

first one:
3x - 5y + z = 12
replace x with (-4 + z -6y)
3(-4 + z -6y) - 5y + z = 12

distribute the 3 and get
-12 +3z -18y -5y +z =12
can you simplify this ?

Answer 30

ya one sec

Answer 31

\[-12+4z-13y=12\]

Answer 32

I would move the -12 to the other side

Answer 33

oh ok

Answer 34

and write the terms alphabetical just so it is easier to match things up

Answer 35

ok

Answer 36

so \[-13y+4z=24\]

Answer 37

and double check your arithmetic on the y term

Answer 38

13y not -13y

Answer 39

?

Answer 40

3x - 5y + z = 12
replace x with (-4 + z -6y)
3(-4 + z -6y) - 5y + z = 12
-12 +3z -18y -5y +z =12

Answer 41

collect terms:

-18y -5y +3z + z = 12+12

if you factor out y and z you get:
(-18-5)y + (3+1)z = 24

Answer 42

-18 + -5 = ?

Answer 43

-23

Answer 44

-23y+4z=24

Answer 45

yes. Be careful with the arithmetic or you'll never get the correct answer, even though you understand the algebra.

Answer 46

now see if any of the choices has that equation.

Answer 47

ok i got the answer

Answer 48

can you help me with another

Answer 49

If more than one answer had that, we would do the 3rd equation.
The 3rd equation turns into -17y=0 (or 17y=0 , or y=0)

Answer 50

ok

Answer 51

heres another

Answer 52

If you were to use the elimination method to solve the following system, choose the new system of equations that would result after the variable z is eliminated in the second and third equations, then the first and second equations.

5x + 2y + z = -2
3x + 4y + 3z = 2
-4x - 3y - 3z = 1

Answer 53

please post it as a separate question

Answer 54

ok