Question

solve the system by substitution
{-x-y-z=-8
-4x+4y+5z=7
2x+2z=4}

Answer 1

2x+2z=4 so (x+z)=2

Answer 2

is this a multiple choice question, are there answers to choose from?

Answer 3

put this in the first equation
-y-(x+z)=-8i.e. -y-2=-8 i.e. y=8-2=6

Answer 4

jango is correct

Answer 5

no, not multiple choice. i have to show my work, but i don't know how to do any of this.

Answer 6

then use the results in equation 2 , which you can write
-4x+4*6+5z=7i.e. -4x+5z=7-24=-17
i.e. 4x-5z=17

Answer 7

now we need to solve x+z=2
and 4x-5z=17,

Answer 8

okay... woah... i mean like, i literally don't know how to do any of this. Everything you've said has gone right over my head...

Answer 9

Do you know what is the method of substitution?

Answer 10

not really, no..

Answer 11

Then you must first learn the theory. :)

Answer 12

could you teach me, oh great & wise one? xD