Question

solve my substitution (medal and fan)

-x - y - z = -8
-4x + 4y + 5z = 7
2x + 2z = 4

Answer 1

rewrite it
-x - y - z = -8
-4x + 4y + 5z = 7
x + z = 2

from 3rd x=2-z
so put in 1st and 2nd one

Answer 2

im still confused :(

Answer 3

i divided the 3rd equation by 2
so have x+y=4/2=2

Answer 4

let start from the begining
-x - y - z = -8
-4x + 4y + 5z = 7
x + z = 2

from 1st equation -x-y-z=-8
-x=-8+y+z
so multiply by -1
x=8-y-z

Answer 5

put x=8-y-z in other equations

-4x + 4y + 5z = 7
x + z = 2

Answer 6

-4(8-y-z) + 4y + 5z = 7
(8-y-z)+ z = 2

Answer 7

can you go on ?

Answer 8

-4(8-y-z) + 4y + 5z = 7
(8-y-z)+ z = 2 --->8-y=2 --->y=6
put that in above

Answer 9

yeah! thankss