Answer:
x + y + z - 3
Step-by-step explanation:
Basically, putting a negative sign before parentheses signifies that you want to flip the sign of everything within the parentheses. This can also be explained by the negative sign representing -1.
Knowing this, we can just multiply everything within by -1.
-y -> y
-z -> z
3 -> -3
We now have y + z - 3, just put this into the original expression and we have our final answer of:
x + y + z - 3
:)