Step-by-step explanation:
I'm not sure if I got the correct answer since English is not my first language
The second one because there is all the inputs are different. There is one input for every output.
It took them 4 days to install 480 chairs which means if they were working at a constant rate they got 120 chairs installed daily. with 360 chairs left that means in 3 days they will finish. so overall, it took the workers 7 days to finish, or a week.
Answer: (30m-9n)/270
First we start with m/9-n/30.
We multiply the denominators to get 270.
Then we multiply the numerators by the original denominators to get (30m-9n).
To check, we can use m=2, and n=4
2/9-4/30=4/45
(30*2-9*4)/270=24/270=4/45
800/6=x/16 6x=12800 divide and get 2133 1/3