Question

Solve the system by substitution.
( I will attach picture. ) *

Answer 1

first rearrange the last equation in terms of x or y.

Answer 2

There are a multitude of ways to go about this.
taking the first equation and solve for x
-y = x + z - 8, or y=-x - z +8 Now substitute for y in 2nd equation
-4x + 4(-x-z+8) + 5z = 7
-4x - 4x -4z +32 +5z = 7
-8x +z = -25 Now take the last equation and solve for x
2x + 2z = 4
2x = -2z +4
x= -z +2 now substitute in -8x + z = -25
-8(-z +2) + z = -25
8z - 16 + z = -25
9z=-25+16
9z=-9
z=-1 substitute for z in 2x + 2z = 4
2x -2 =4
2x=6
x=3

Now substitue for x and z in one of the originals and solve for y

Answer 3

* second line change solve for x to read solve for y.

Answer 4

so , z=-1 , x=3?

Answer 5

That is what I got from the above solving for x take the first one
-x-y-z=-8
-3-y+1=-8
-y=-8+3-1
-y =-6
y=6

Answer 6

First line change x to read y (we had already solved for x)

Answer 7

(3,6,-1)

Answer 8

Thanks alott ! ! (:

Answer 9

You're welcome.