#### Answer

(-4, 3, 1)

#### Work Step by Step

In order to solve systems of three linear equations, we multiply the first and second equation by values that will cancel out a variable when they are added. Thus, we multiply the first equation by -2 and the second equation by 1 and add to obtain:
$-8x -7y = 11$
We now multiply the first and third equation by values that will cancel out a variable when they are added. Thus, we multiply the first equation by 3 and the third equation by one and add to obtain:
$ 16x + 5y = -49 $
Plugging $x = -7/8y -11/8$ into this equation, we obtain:
$-9y -22 = -49 \\ y = 3 $
Now, we plug this value into one of the equations that only has x and y in them to find:
$ x = -4$
Finally, we plug the values of x and y into the first equation listed in the book to find:
$ z = 1$