The average swimming pool has a volume of about 28,000 gallons. Suppose a swimming pool was filled with pH 7.00 water. However, you need to adjust the pH to 4.75. How much acid pool acid (which is 1.00 M HCl) do you need to add to the pool? The units are liters.

convert 28000divided 3.785=105980
(10-7)(105980)=?
(10-4.75)=?

I think you converted the wrong way.

28,000 gallons x (3.785 L/gallon) = 1E5 ESTIMATED. You need a better answer than that.
How many mols do you need? That's M x L = approx 1E5 mol HCl.
M HCl = mols HCl/L HCl. You know M and mols, solve for L. That really looks like a simple problem to me. Think in mols. That's the secret to most chemistry problems.

To calculate the amount of acid pool acid (1.00 M HCl) you need to add to the pool, you need to follow these steps:

1. Convert the volume of the swimming pool from gallons to liters. Since 1 gallon is approximately equal to 3.785 liters, you can convert 28000 gallons to liters by dividing it by 3.785:

28000 gallons / 3.785 = 7396.4 liters (rounded to one decimal place)

2. Calculate the difference in pH between the current pH (7.00) and the desired pH (4.75):

pH difference = current pH - desired pH = 7.00 - 4.75 = 2.25

3. Multiply the pH difference by the volume of the pool in liters to get the total amount of acid pool acid needed:

acid needed = pH difference * volume of the pool in liters = 2.25 * 7396.4 = 16641.9 liters (rounded to one decimal place)

So, you will need to add approximately 16641.9 liters of 1.00 M HCl acid to adjust the pH of the pool from 7.00 to 4.75.