Write any two numbers less than 15 , which has exactly four factors

Which expressions are equivalent to -6 + 3m

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Don't know how to find x given these segment lengths