Could you guys please help me answer the following questions based on the picture. Thank you :)

Find the least common denominator for thesetvo rational expressions.n^2/n^2+4n+4 -3/n^2+7n+10

Collin did the work to see if 10 is a solution to the equation r/4=2.4

Tom travels between the two mile markers shown and then finds his average speed in miles per hour. select the three equations that represent this situation.