Question

sytem of linear equations solve
x+y+4z=-11
x+y+6z=-15
x+8y+8z=-26

Answer 1

Hint, isolate z in the first equation, then substitute the expression for z into the last two equations.

Answer 2

We shall begin by getting rid of the x.
x+y+4z=-11
-1(x+y+6z=-15) <-- Must make it negative to cancel it out

x+y+4z=-11
-x-y-6z=15 <-- New equation after you multiply the -1
= -2z=4 z=-2

Now you solve for the other equation.

x+y+4z=-11
-x-8y-8z=26
Answer= -7y-4z=15 <-- Plug in -2 for z

-7y+8=15
y=-1

plug in -2 for z and -1 for y in any of the first 3 starting equations to solve for x.