Answer: As my guess is D.
Step-by-step explanation: Sorry if I'm wrong.
Answer:
3xyz
Step-by-step explanation:
The required sum = 7xyz+(−5xyz)+9xyz+(−8xyz)
=7xyz–5xyz+9xyz–8xyz
=(7–5+9–8)xyz
=(16–13)xyz
=3xyz
y=11x-47
And find it all urself
hope this is correct