The whiteboards she bought cost $35, and she spent a total of $51.20, subtract to find out the total amount she spent on posters:

So she spent a total of $16.20 on posters, now divide by the amount one poster costs to find out how many posters she bought.

So she bought 3 posters.
A function is a relation in which each possible input value leads to exactly one output value
I gallon of water per 1 inch of fish
lemon tetra is 2 inches long
so 1 lemon tetra for 2 gallons of water
20/2 = 10
they can have 10 of them
equation would be X = 20/2
Y = k/x for some fixed number constant k
7 = k/9
k = 63
so Y = 63/x
14 = 63/x
14 x = 63
x = 63/14 = 9/2
Answer:
Domain of a geometric or arithmetic sequence is the counting numbers unless otherwise noted.