The table show the total distance d, in miles, a car traveled after t hours

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Could somebody me with this radical simplification?

According to the 2008 u. s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.