Which expression represents the sum of 21 and an unknown number?

A. 21-d

B. 21+d

C. 21:d

D. 21d

How many inches are in a foot

At Brian's bookstore three tenths of the show some mysteries 25% shelves hold travel books, and 7 over 20 of the shelves hold children's books. Which type of book covers the most shelf space in the store?

Calculate the difference and enter it below. 5 - (-5) Answer here

What would be the answer to. 99x=.89x-10

6. A proportion is an equation showing two equal ratios. Give an example

What are the steps towards finding the answer to 1 - 9n = - 80

12d-2d+e. In other words, what is 12d subtracted by 2d and added e? Just learning this now I am a bit confused

3 wholes and 1/2 + 8 wholes 1/3 reduce to lowest terms

A sociology professor assigns letter grades on a test according to the following scheme. A: Top 13% of scores B: Scores below the top 13% and above the bottom 59% C: Scores below the top 41% and above the bottom 23% D: Scores below the top 77% and

3. Nick is on his school's track team. He can run 2 miles in 16 minutes. At this rate, how many minutes would it take Nick to run 6 miles? A 8 B. 32 C. 48 D. 96