Question

.

Answer 1

pic is not working :(

Answer 2

use substitution {x = 4, y = -1, z = -3}

Answer 3

http://i49.tinypic.com/se3r04.jpg

Answer 4

still not shown up

Answer 5

well it looks like this
3x+2y+z=7
5x+5y+4z=3
3x+2y+3z=1 with the { in front of it it

Answer 6

use elimination. We can write down just the numbers

3 2 1 7
5 5 4 3
3 2 3 1

Here are the first 2 steps:
multiply the first row by -5/3 and add to the 2nd row
multiply the first row by -1 and add to the 3rd row

can you do that?