Question

two years ago the water in a local reservoir fell 8 3/4 feet then it rose 4 3/5 how much did it change

Answer 1

The total change in the local reservoir's water level is a decrease of 4 3/20 feet, after considering both the decrease and subsequent increase in the water level.

Step-by-step explanation:

The student asked how much the water level changed in a local reservoir after it fell by 8 3/4 feet and then rose by 4 3/5 feet. To calculate the total change in water level, we should find the difference between the decrease and the increase. We convert the mixed numbers into improper fractions for easy calculation. 8 3/4 feet is the same as 35/4 feet and 4 3/5 feet is the same as 23/5 feet. Subtracting the increase from the decrease gives us (35/4) - (23/5) feet.

Now, we find a common denominator, which in this case is 20, and rewrite the fractions: (35/4) × (5/5) = 175/20 and (23/5) × (4/4) = 92/20. Subtracting these, we get 175/20 - 92/20 = 83/20, which simplifies to 4 3/20 feet.

The total change in the water level of the local reservoir is a decrease of 4 3/20 feet.

Answer 2

To find the change, we need to subtract.

8 3/4 - 4 3/5

We need a common denominator to find the answer.

3*5/4*5 = 15/20

8 15/20

3*4/5*4 = 12/20

4 12/20

Now we can properly subtract

8-4=4

15-12
-------- =
20

3/20

Now we have our final answer: 4 3/20

The change : 4 3/20