Question

i need a step by step tutorial on how to do 3-variable equations... i learned how to at school and i got a take home test and every answer i do comes out wrong. anyone want to help?

Answer 1

you mean 3 variable 3 equations system?

Answer 2

im not sure what theyre called. it looks like this:
x+y+z=1
2x+y=4
x+z=6
( i made that up)

Answer 3

x+y+z=1
2x+y=4
x+z=6

reduce that to two equation

z=-x+6

plug in first equation for z

x+y+(-x+6)=1
2x+y=4

now you got two equation and two unknown which is easier to solve

Answer 4

so if my question was
x-2y=1
x+3y+1z=0
2x-2x=18
would my 2 new equations be
5y+1z=-1
and
8x-y=11
?

Answer 5

show me what you did, like what did you subsitute

Answer 6

i did
x-2y+0z=1
x+3y+1z=0
but then i had to multiply by -1 in order to substitute the x
so then i got
-x+2y-0z=-1
x+3y+1z=0
which is when i got my first new equation
5y+1z=-1

for the second one i did
x+3y+1z=0
2x+0y-2z=18
but i had to multiply by -2 to get rid of the x
so i got
-2x-6x-2z=0
2x+0y-2z=18
which is when i got my 2nd new equation
-6y-4z=18