5.3.21
Solve the equation P= r+t+s for r
(Simplify your answer.)

   r = P -t -s

Step-by-step explanation:

This is a one-step linear equation in r. Subtract the terms that don't contain r:

  P = r + t + s . . . . . . . . . .  given

The terms on the right that don't include r are (t+s). We want to subtract that to get r by itself.

  P -(t+s) = r +(t+s) -(t+s) . . . subtract (t+s)

  P -t -s = r . . . . . . . . . . . . . . simplify

  r = P - t - s

take it another

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.