Question

solve the system by substitution

Answer 1

start with easiest system and solve for a variable, then once you have that variable you can plug back into the same equation to get the other variable once you have those then you can plug into the other systems and solve for the third variable.

Answer 2

I used the first equation and got -y=-8+x+z but Im not sure how to get rid of the -y and get a positive y

Answer 3

divide both sides by the negative and change the signs of the terms if applicable

Answer 4

I divided by -1 and got y=8-x-z, is that correct?

Answer 5

assuming your initial -y=-8+x+z is the correct, yes y=8+x+z is correct.

Answer 6

I would of started with the last system 2x+2z=4 and solved for x. to get x=2-z

Answer 7

maybe that will be easier, thank you for helping. if I tell you what I get can you check it?

Answer 8

then you can plug x back into the equation to get z, and so on...

Answer 9

sure

Answer 10

I tried plugging x back into the equation and got 4-2z+2z=4 but if I combine like terms z will become 0

Answer 11

Im not supposed to simplify all the way yet huh? Im just supposed to make new equations

Answer 12

my apologies, yes that's correct it should equal zero you then solve for z the same way you solved for x which will be z=2-x so then with both those variables solved plug them into the next equation and go on from there.

Answer 13

wait, I still plug in x into the same equation or a different one ?

Answer 14

after plugging in the other two I got y=5x-3/4

Answer 15

then I believe you should be able to plug those into the first equation

Answer 16

so you will have x, y, and z, and plug into the first equation.

Answer 17

so it should be -(2-z)-(5x-3/4)-(2-x)=-8

Answer 18

then distribute if you need to otherwise I think that should be the answer.

Answer 19

wait, how did you get z=2-x? like what equation did you plug x into?

Answer 20

I just solved the same equation that you get the x from 2x+2z=4
2x+2z=4
-2x -2x
2z=4-2x
/2 /2
z=2-x

Answer 21

I didn't work the last equation with all three variable but you should get a value for each variable by solving for each.

Answer 22

alright, thank you

Answer 23

once you get all the variables distributed and simplified you should get 4z-x-21=-32y
and from there you can solve for each variable.

Answer 24

alright, I think I got it. Thank you so much for helping

Answer 25

sure