Mattie has a swimming pool. She put a rectangular fence around the pool. How many feet of fencing did she use if the length of the pool is 21 feet by 16 feet?

I assume you mean the lengths and widths are 21 and 6 feet, so we need to find the perimeter, which would be 21+21+6+6=54 right?

Step-by-step explanation:

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )