Question

I am really confused!
Solve the system by substitution.
-x - y - z = -8
-4x + 4y +5z = 7
2x + 2z = 4

Answer 1

Step 1: Take the first equation and solve for a variable.
x= -y-z+8

Step 2: Plug the new equation into a different equation and simplify. [[I will plug it into the 3rd equation]]
2(-y-z+8)+2z=4
-2y-2z+16+2z=4
-2y+16=4
-2y=-12
y=6

Answer 2

Step 3: Plug in x and y into the last equation.
-4((-6)-z+8)+4(6)+5z=7
24+4z-32+24+5z=7
16+9z=7
9z=-9
z=-1

Answer 3

Step 4: Plug in y and z into the original equation
-x-(6)-(-1)=-8
-x-6+1=-8
-x-5=-8
-x=-3
x=3

Answer 4

SO x=3, y=6, and z=-1

Answer 5

Thank you so much for breaking it down for me. That makes a lot of sense!