If i'm correct you should add 0.5 mL to your 1 gallon tank, and I would say about 1.25 mL to your 2.5 gallon. It will not be extreme if you end up putting a little more in than you are supposed to. I'm not 100% because i haven't slept so my brain is being slow.
First, let's find all the factors of 81:
81/3=27
27/3=9
9/3=3
3/1=1
So the factors of 81 are 3,3,3,3, (the numbers by which we divided here).
This means we can write down 81 as 3*3*3*3 or

- which is the answer to the question! (three to the power of 4)
Step-by-step explanation:
First multiply
9w - 18 = - 18
9w = - 18 + 18
9w = 0
w = 0 / 9 = 0
w = 0
Answer:
B,C, and D
Give thanks and brainliest!! :P
I think the answer is 1.97 hope it helps you