Question

Solve the system by substitution. -x-y-z=-8
-4x-4y+5z=7
2x+2x=4

Answer 1

put 2 of them on top of each other

Answer 2

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

Answer 3

hmm wait never mind this is a different one that is much simpler ignore that top stuff

Answer 4

2x+2x=4 simpliy 4x=4 divide by 4 and you get x=1

Answer 5

now take either one of the equations and substitute x, lets pick the first one

Answer 6

-x-y-z=-8 substitute and you get -(1)-y-z=-8

Answer 7

move the -1 to the right by adding it to both sides and you get -y-z=-8+1 or -y-z=-7

Answer 8

get y by itself y=z-7

Answer 9

now in the second equation substute both x and y

Answer 10

-4x-4y+5z=7 subsitute and you get -4(1)-4(z-7)+5z=7

Answer 11

simplify, -4-4z+7z+5z=7

Answer 12

sorry -4-4z+7+5z=7

Answer 13

combine like terms

Answer 14

3+1z=7

Answer 15

move the 3 to the other side and you get z=4

Answer 16

then plug it into the other one and you get y=z-7 or y=4-7

y=-3

Answer 17

POk I'm with you so far

Answer 18

so together x=1 y=-3 and z=4

Answer 19

Thank you a lot man

Answer 20

no problem