Answer
$-1$
Work Step by Step
RECALL:
$a-(-b)=a+b$
Substitute the given values of the variables to obtain:
$-x+y-z = -3+(-4)-(-6)$
Perform the addition (which is the furthest left in the equation) first to obtain:
$=-7-(-6)$
Use the rule above to obtain:
$=-7+6
\\=-1$
