What does the question mean? For the blank

Absolute value.

Step-by-step explanation:

We have the expression:

The square root and the square will cancel. This yields:

We need the absolute value because any value squared is positive. The square root of a positive value will also be positive.

In other words, if we only simplified the expression down to s without the absolute value, if s was originally negative, our simplification will have also been negative.

For instance, say s = -7, then:

However, if we let √s² = s, then s = -7. By having the absolute value, we have that |s| = |-7| = 7, which is the correct statement.

b

step-by-step explanation:

b

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.