Two numbers have a sum of zero and have a distance of 2.5 units between them on the number line, what are they?

What is the answer to this problem 7 * 5/6

The diameter of a table is 5 feet. what is the circumference

Roger and natalie travel in similar cars. roger's car drives the two miles to school in 7.5 minutes. natalie drives the same distance in the opposite direction but in only 6.5 minutes. what is true of their velocities?