Chapter 10 - Section 10.2 - Systems of Linear Equations in Several Variables - 10.2 Exercises - Page 697: 9

(4,0,3)

To solve for z in the last equation divide both sides by 2. When we do so we see z is 3. Substituting it into the second equation we get $-y+9=9$. Thus y is 0. We substitute these variables into the first equation. We get $x + 3 =7$ . x is 4.