Hey there!
Basically it wants you to add 3 and 8 from each other, what ever the answer to that part, you multiply the result by 9
Here this is what i meant

Or you could do this method too!

They both give you the result of 
So, I am assuming your expression would look like this: 
Good luck on your assignment and enjoy your day!
~
I’m not sure but I’m guessing it could be 8 ft
17. Its answer C i wil tell you the other one in a sec
The numbers are 5 and 2.
Reciprocals: 5- 5/10
2- 2/10
(2/10)+(5/10)= 7/10
5-2= 3
Answer: 5 and 2