1. The combined volume of all the tanks at the aquarium is written in Scientific notation. Keeping this on mind, you can write it as following:

2. Now, you must sum the combined volume of all the tanks and the volume of the new tank to calculate the total volume of all of them:
3. Now, you can write the result in Scientific notation, as following:

The answer is: 
A) 24
All side lengths of a square are equal so you take the square root of 576 to get two 24. If you try it back: 24*24 (w*h) to get 576.
If 10% was added to the total (100%), then subtract 10% from 17.85.
17.85 * 0.1 = 1.785
17.85 - 1.785 = 16.065
$16.07
Y – y1 = m(x – x1)
y-(-1)=-5(x-2)
Y+1=-5(x-2)