Question

find the system of equations
-x+y-z=0
x+2y+z=9
y+z=5

Answer 1

-x+y-z=0
x+2y+z=9
y+z=5

You can add together the first two equations, to eliminate y and z. After adding the first two, you have:

-x+y-z=0
3y=9 (our new second equation after adding the first and second)
y+z=5

Now notice you can just solve the last two equations:

3y=9
y+z=5

Answer 2

so y =3

Answer 3

and z=2

Answer 4

x=-1.?

Answer 5

Yes, yes, no. x will be a whole number. Use -x+y-z=0 to find x, it's the easiest way.

Answer 6

Oh, you said x=1, yes that's right.