(1/12)X = 6800
6800/ (1/12) = X
X = 81600 (hours)
6800 (6.8 * 10^3) divided by 1/12 (12^-1) equals 81600. It will take 81600 hours for the pool to completely empty at a rate of 0.833333333 or 12^-1 gallons per second.
1st one : is 1/4 ( subtract 3/8 from both sides and simplify 5/8 - 3/8 to 1/4. )
2nd one : is 1/2 ( subtract 3/4 from both sides, simplify 1/4 - 3/4 to 1/-2, and then multiply both sides by -1 )
3rd one : is 5/6 ( subtract 1/8 from both sides and simplify 23/24 - 1/8 to 5/6).
100 it's like the absolute value