Answer
$-10$
Work Step by Step
RECALL:
$a+(-b)=a-b$
Substitute the given values of the variables to obtain:
$x-y+z = 5-6+(-9)$
Use the rule above to obtain:
$=5+(-6)+(-9)$
Combine the negative numbers to obtain:
$=5 + (-15)$
Add to obtain:
$=-10$
