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!
~
40 % off means we pay 60 % (must total 100%)
original price * 60 % = 36.00
change percent to decimal
original price * .6 = 36
divide each side by .6
orginal price = 60
Answer:
x = 3
Step-by-step explanation:
6x - 4 = 2x + 8
6x - 2x = 8 + 4
4x = 12
x = 12/4
x = 3
Whats the question here if your wondering how many shells she finds in a certain amout of days just get a calculator and keep adding 12 over and over again